late 14c., first attested in Scottish English, apparently a dialectal variant of Scottish stob "to pierce, stab," of uncertain origin, perhaps a variant of stub (n.) "stake, nail." Figurative use, of emotions, etc., is from 1590s. Related: Stabbed; stabbing.
"wound produced by stabbing," mid-15c., from stab (v.). Meaning "a try" first recorded 1895, American English. Stab in the back "treacherous deed" is first attested 1916.
Betrayal; harming someone in a treacherous way • Also verb phrase (1916+)