Green’s Dictionary of Slang

sonofabitch n.

also bitch’s son, sombitch, son, sonabitch, son-a-fa-bitch, sonbitch, sonnomo bitzah, sonn’vabitch, sonobitch, sonofabastard, sonofabee, son of a big-shoe, son of a bitch, son-of-a-bitch-of-a-bastard, son of a dog, son of a French bastard, son of a hurry, son of a lady dog, son of a two-legged dog, son of a whore, sonofawhore, son of the bitch, sonovabitch, sonumbitch, sonuvabitch, sonvbitch, sumbitch, sumph, sunabitch
[coined c.1330 in the form Biche-sone and in its current form in Shakespeare’s King Lear (1605). Like a number of otherwise derog. terms (cf. bastard n.; motherfucker n.), it can be used affectionately and of a woman, albeit rarely, as well as of a man. It can also be used as a general non-specific referent meaning ‘thing’, e.g. pass the sonofabitch over here]

1. [17C+] a derog. general term of abuse.

2. [late 19C] (Aus.) a moustache, as worn by cattle-buyers and wool inspectors.

3. [1910s] (US) a stew.

4. [mid-19C; 1920s+] an affectionate term of address; also used self-reflexively.

5. [1930s+] something or someone exceptional.

6. [1940s+] a thing, ‘it’.

In phrases

In exclamations

I’ll be a sonofabitch!

[20C+] a general excl. of surprise or annoyance.