Green’s Dictionary of Slang

mammox v.

[dial. mammock, to tear into pieces]
(US, mainly Western and Southern)

to beat, to thrash; thus mommicking, a thrashing.

Show quotations
[US]Ely’s Hawk & Buzzard (NY) Mar. 22 2/1: I will mammoc you into a mince colop.
With the Commanches (in Schele De Vere 1872) He was right smartly mammoxed, and at first we thought he was done for, but the damage wasn’t very great, after all.
[US]Schele De Vere Americanisms 616: Mammoxed means, in Southern and Western slang, to be seriously injured. The origin of the term is not very clear – if it ever had a legitimate pedigree outside of Shakespeare’s mummocked.