Anomie, in contemporary English language, is a sociological term which may most simply be described as a personal condition resulting from a lack of norms. For Émile Durkheim, a lack of social ethic produces moral deregulation and an absence of legitimate aspirations. Though anomie is commonly associated with low regulation, Durkheim postulated that overly rigid (e.g. totalitarian) societies would also produce anomic individuals:
Anomie in common parlance is thought to mean something like "at loose ends." The Oxford English Dictionary lists a range of definitions, beginning with a disregard of divine law, through the 19th and 20th century sociological terms meaning an absence of accepted social standards or values. Most sociologists associate the term with Durkheim, who used the concept to speak of the ways in which an individual's actions are matched, or integrated, with a system of social norms and practices ... Durkheim also formally posited anomie as a mismatch, not simply as the absence of norms. Thus, a society with too much rigidity and little individual discretion could also produce a kind of anomie, a mismatch between individual circumstances and larger social mores. Thus, fatalistic suicide arises when a person is too rule-governed, when there is … no free horizon of expectation. 
In 1893 Durkheim introduced the concept of anomie to describe the mismatch of collective guild labor to evolving societal needs when the guild was homogeneous in its constituency. He equated homogeneous (redundant) skills to mechanical solidarity whose inertia retarded adaptation. He contrasted this with the self-regulating behavior of a division of labor based on differences in constituency, equated to organic solidarity, whose lack of inertia made it differentially sensitive to need changes.
Durkheim observed that these two labour forms could not co-exist. The conflict between the evolved organic division of labor and the homogeneous mechanical type was such that one could not long exist in the presence of the other:“This social type rests on principles so different from the preceding that it can develop only in proportion to the effacement of that preceding type.” and “The history of these two types shows, in effect, that one has progressed only as the other has retrogressed.” 
When solidarity is organic, anomie is “impossible whenever solidary organs are sufficiently in contact or sufficiently prolonged. In effect, being contiguous, they are quickly warned, in each circumstance, of the need they have of one another, and, consequently, they have a lively and continuous sentiment of their mutual dependence. For the same reason that exchanges take place among them easily, they take place frequently, and in time the work of consolidation is achieved.” Their sensitivity to mutual needs promotes the evolution in the division of labor “because the smallest reaction can be felt from one part to another. ... they foresee and fix, in detail, the conditions of equilibrium."  "Producers, being near consumers, can easily reckon the extent of the needs to be satisfied. Equilibrium is established without any trouble and production regulates itself.”
Durkheim contrasted the condition of anomie as being the result of mechanical solidarity: "But on the contrary, if some opaque environment is interposed, then only stimuli of certain intensity can be communicated from one organ to another. Relations being rare, are not repeated enough to be determined; each time there ensues new grouping. The lines of passage taken by the streams of movement cannot deepen because the streams themselves are too intermittent.” “Contact is no longer sufficient. The producer can no longer embrace the market at a glance, nor even in thought. He can no longer see its limits, since it is, so to speak limitless. Accordingly, production becomes unbridled and unregulated.”
Durkheim's use of the term anomie was about a phenomenon of industrialization—mass-regimentation that could not adapt due to its own inertia—its resistance to change, which causes disruptive cycles of collective behavior (e.g. economics) due to the necessity of a prolonged buildup of sufficient force or momentum to overcome the inertia.
Later in 1897, in his studies of suicide, Durkheim associated anomie to the influence of a lack of norms or norms that were too rigid. But such normlessness or norm-rigidity was a symptom of anomie, caused by the lack of differential adaptation that would enable norms to evolve naturally due to self regulation, either to develop norms where none existed or to change norms that had become rigid and obsolete.
The importance of Durkheim's earlier definition is its specificity of the direct cause of a collective social disorder that has great relevance in the understanding of economic imbalance, labor obsolescence, mass movements, and many great themes in history and literature, such as those of H.G. Wells, Aldous Huxley, and George Orwell.
The word comes from Greek, namely the prefix a- “without”, and nomos “law”. The Greeks distinguished between nomos (νόμος, “law”), and arché (αρχή, “starting rule, axiom, principle”). For example, a monarch is a single ruler but he or she might still be subject to, and not exempt from, the prevailing laws, i.e. nomos. In the original city state democracy, the majority rule was an aspect of arché because it was a rule-based, customary system which might or might not make laws, i.e. nomos. Thus, the original meaning of anomie defined anything or anyone against or outside the law, or a condition where the current laws were not applied resulting in a state of illegitimacy or lawlessness.
The contemporary English understanding of the word anomie can accept greater flexibility in the word “norm”, and some have used the idea of normlessness to reflect a similar situation to the idea of anarchy. But, as used by Émile Durkheim and later theorists, anomie is a reaction against or a retreat from the regulatory social controls of society, and is a completely separate concept from anarchy which is an absence of effective rulers or leaders.
As social disorder
The nineteenth century French pioneer sociologist Émile Durkheim borrowed the word from French philosopher Jean-Marie Guyau and used it in his influential book Suicide (1897), outlining the social (and not individual) causes of suicide, characterized by an absence or diminution of standards or values (referred to as normlessness), and an associated feeling of alienation and purposelessness. He believed that anomie is common when the surrounding society has undergone significant changes in its economic fortunes, whether for good or for worse and, more generally, when there is a significant discrepancy between the ideological theories and values commonly professed and what was actually achievable in everyday life. This is contrary to previous theories on suicide which generally maintained that suicide was precipitated by negative events in a person's life and their subsequent depression.
In Durkheim’s view, traditional religions often provided the basis for the shared values which the anomic individual lacks. Furthermore, he argued that the division of labor that had been prevalent in economic life since the Industrial Revolution led individuals to pursue egoistic ends rather than seeking the good of a larger community. Robert King Merton also adopted the idea of anomie to develop Strain Theory, defining it as the discrepancy between common social goals and the legitimate means to attain those goals. In other words, an individual suffering from anomie would strive to attain the common goals of a specific society yet would not be able to reach these goals legitimately because of the structural limitations in society. As a result the individual would exhibit deviant behavior. Friedrich Hayek notably uses the word anomie with this meaning.
Anomie as a social disorder is not to be confused with anarchy. Anarchy denotes lack of rulers, hierarchy, and command, whereas anomie denotes lack of rules, structure, and organization. Many proponents of anarchism claim that anarchy does not necessarily lead to anomie and that hierarchical command actually increases lawlessness (see e.g. the Law of Eristic Escalation). As an older variant, the Webster 1913 dictionary reports use of the word anomie as meaning “disregard or violation of the law”.
In literature, film and theater
In Albert Camus’s existentialist novel The Stranger, the bored, alienated protagonist Meursault struggles to construct an individual system of values as he responds to the disappearance of the old. He exists largely in a state of anomie, as seen from the apathy evinced in the opening lines: “Aujourd’hui, maman est morte. Ou peut-être hier, je ne sais pas” (“Today mother died. Or maybe yesterday, I don't know.”). When Mersault is prosecuted for shooting an Arab man during a fight, the prosecuting attorneys seem more interested in the inability or unwillingness of Meursault to cry at his mother's funeral than the murder of the Arab, because they find his lack of remorse offensive. The novel ends with Meursault recognizing the universe's indifference toward humankind. In the first half of the novel Meursault is clearly an unreflecting, unapologetic individual. Ultimately, Camus presents the world as essentially meaningless and therefore, the only way to arrive at any meaning or purpose is to make it oneself.
Dostoevsky, whose work is often considered a philosophical precursor to existentialism, often expressed a similar concern in his novels. In The Brothers Karamazov, the character Dmitri Karamazov asks his atheist friend Rakitin, ”...without God and immortal life? All things are lawful then, they can do what they like?”. The novel explores the existence of God, the nature of truth, and the importance of forgiveness through the actions of its characters. Raskolnikov, the anti-hero of Dostoevsky’s novel Crime and Punishment, puts this philosophy into action when he kills an elderly pawnbroker and her sister, later rationalizing this act to himself with the words, “...it wasn’t a human being I killed, it was a principle!” Raskolnikov's inner conflict in the opening section of the novel results in a utilitarian-altruistic justification for the proposed crime: why not kill a wretched and "useless" old moneylender to alleviate the human misery?
Hermann Hesse’s Der Steppenwolf also expresses a picture of anomie. The novel tells the story of a middle-aged man named Harry Haller who beset with reflections on his being ill-suited for the world of "everybody", the regular people. In his aimless wanderings about the city he is given a book which describes the two natures of man: one "high", spiritual and "human"; while the other is "low" and animal-like. Thus, man is entangled in an irresolvable struggle, never content with either nature because he cannot see beyond this self-made construct. While Haller longs to live free from social convention, he continually lives as a bourgeois bachelor. Haller argues that the men of the Dark Ages did not suffer more than those of the Classical Antiquity, and vice-versa. It is rather those who live between two times, those who do not know what to follow, that suffer the most. In this token, a man from the Dark Ages living in the Classical Antiquity, or the opposite, would undergo a gulping sadness and agony.
The characters Vladimir and Estragon in Samuel Beckett's absurdist play Waiting For Godot express a sense of anomie. The play follows two consecutive days in the lives of a pair of men who divert themselves while they wait expectantly and unsuccessfully for someone named Godot to arrive. Frustrated at the long wait, they think of what to do to pass the time. Estragon suggests that they hang themselves, but since they are concerned that they might not both die, they decide to do nothing: "It's safer," explains Estragon. Another character, Lucky, describes an impersonal and callous God, asserts that man 'wastes and pines', mourns an inhospitable earth, and claims that man diminishes in a world that does not nurture him." The play illustrates an attitude toward man's experience on earth: the poignancy, oppression, camaraderie, hope, corruption, and bewilderment of human experience that can only be reconciled in mind and art of the absurdist.