an insult used by the very clever people (note the sarcasm) who realised that the word witch rhymes with the word bitch. a derogatory term for someone who practises witchcraft.
person 1: oi!!!!
*person 2 continues walking*
person 1: im talking to you, witch!!!
person 2: fuck off, asshole!!!
person 1: what did you say witchbitch!!!
person 2: you heard me.......asshole!!!