go apeshit verb1 •(slang, vulgar) To behave in an extreme manner; to act without restraint, especially by becoming explosively angry.Dexter's vocals are competent enough: his timbre is thin and eternally teenaged, but he can go apeshit on the hiccupy histrionics like no one's business. — 1999 formswent apeshit · gone apeshit · going apeshit · goes apeshit