Urinates, or in informal usage, angers or irritates someone greatly.
From Old French 'pissier,' possibly imitative of the sound or from Latin 'pisciare.' The slang meaning 'to anger' developed in modern English from the general sense of being bothered or disturbed.
This humble four-letter word has survived centuries of linguistic censorship to remain one of the few crude terms nearly every English speaker knows—it's so taboo-yet-essential that it appears in Shakespeare and Chaucer but was censored from children's books until recently. The shift from literal to figurative meaning (angry vs. urinating) is one of the strongest emotional extensions in English slang.
Complete word intelligence in one call. Free tier — 50 lookups/day.