In fiction, an antihero (feminine: antiheroine) is a protagonist whose character or goals are antithetical to traditional heroism. The term dates to 1714, although literary criticism identifies the trope in earlier literature. 
There is no definitive moment when the antihero came into existence as a literary trope. The antihero has evolved over time, changing as society’s conceptions of the hero changed, from the Elizabethan times of Faust and William Shakespeare's Falstaff, to the darker-themed Victorian literature of the 19th century, such as John Gay's The Beggar’s Opera or as a timid, passive, indecisive man that contrasts sharply with other Greek heroes  to Philip Meadows Taylor's Confessions of a Thug. The Byronic hero also sets a literary precedent for the modern concept of antiheroism.
Distinction from Byronic and tragic heroes
The Byronic hero is a rebellious antihero who is sympathetic despite his rejection of virtue. 
Antiheroes differ from Tragic heroes because a tragic hero is still primarily heroic but with a major tragic flaw, while an antihero’s flaws are more prominent than their heroic qualities.
also n., pl. -roes also -roes.
A main character in a dramatic or narrative work who is characterized by a lack of traditional heroic qualities, such as idealism or courage.
antiheroic an’ti·her·o’ic (-hĭ-rō’ĭk) adj.
antiheroism an’ti·her’o·ism (-hĕr’ō-ĭz’əm) n.
anti‐hero or anti‐heroine, a central character in a dramatic or narrative work who lacks the qualities of nobility and magnanimity expected of traditional heroes and heroines in romances and epics. Unheroic characters of this kind have been an important feature of the Western novel, which has subjected idealistic heroism to parody since Cervantes’s Don Quixote (1605). Flaubert’s Emma Bovary (in Madame Bovary, 1857) and Joyce’s Leopold Bloom (in Ulysses, 1922) are outstanding examples of this antiheroic ordinariness and inadequacy. The anti‐hero is also an important figure in modern drama, both in the theatre of the absurd and in the tragedies of Arthur Miller, notably Death of a Salesman (1949). In these plays, as in many modern novels, the protagonist is an ineffectual failure who succumbs to the pressure of circumstances. The anti‐hero should not be confused with the antagonist or the villain.
> > anti-hero, principal character of a modern literary or dramatic work who lacks the attributes of the traditional protagonist or hero. The anti-hero’s lack of courage, honesty, or grace, his weaknesses and confusion, often reflect modern man’s ambivalence toward traditional moral and social virtues. Literary characters that can be considered anti-heroes are: Leopold Bloom in James Joyce’s novel Ulysses
(1922), Willy Loman in Arthur Miller’s play Death of a Salesman
(1949), the bombardier Yossarian in Joseph Heller’s novel Catch-22
(1961), and the protagonists of many of Philip Roth’s and Kurt Vonnegut’s novels.