periodal Share definition Flag A woman's behavior during her period (moody, super emotional, abnormally jealous, etc) Girlfriend: Why would you play a joke on me like your cheating? You know I'm all periodal and shit. Boyfriend: Periodal already? Dayyyum periodal by msdirt40 October 25, 2013 0 0 Get merch Get the periodal mug. Buy Now — $32.95 See more merch