1. [1920s+] a supreme insult, an expletive based on the incest taboo, prob. the ultimate in obscenities [dating is difficult, the earliest written citation is in 1918, although R.S. Gold, Jazz Lexicon (1964) notes the term was in existence as early as c.1900].
2. [1940s+] (orig. US) anything one dislikes, an infuriating or surprising state of affairs.
3. [1950s+] (orig. US black) used with a wide variety of meanings, from good to bad, often as a black-to-black term of affection or a compliment, e.g. Jimi Hendrix was a bad motherfucker on guitar; also simply meaning ‘thing’. Frequently abbr. to mother [note Folb, Runnin’ Down Some Lines (1980) ‘You jus’ be sayin’ dat any way come to your mind. Like you got some o’ dem sweet mothafuckas. They righteously together brothers, got they game uptight, they on dey J.O.B.! Right on! Got dem lowlife thugs. They mean mothas. Don’t be messin’ wid ’em. Blow you away in a minute! Johnny he my ace, now he a bad mothafucka. He together. Strong rap to d’ young ladies – and he go down wi’chu right now! We tight. Gots dem little ol’ punks. Think they together, be talkin’ out d’ side dey neck! Jive mothafucka don’t hold no air! See like da’s one o’ dem slangs got all differn’ kin’a meaning. Don’t be callin’ young lady dat. Dude use dat talk ’bout other dude’].
4. [1960s+] a thing, otherwise unnamed.
5. [1960s+] an indefinite standard of comparison, e.g. crazy as a motherfucker; meaner than a motherfucker; as adv.
6. [1970s+] a large or outstanding example.
7. [1990s+] a place.
[1960s+] (orig. US black) an intensifying expletive; thus he has guns for a motherfucker, he has a great many guns; I’m throwing bricks for a motherfucker, I’m throwing bricks continually and passionately etc.
[1960s+] (orig. US black) a general intensifier.
[1960s+] an excl. of commitment, usu. followed by ‘if’ and some form of negative statement.