regretamin Share definition Flag Another derogatory term for ketamine. specifically denotes a k sesh that results in embarrassment or regret. "Bobby mate how'd you get all those fag burns on your face??" "errrr.....that'll be the regretamin" regretamin by mandingo89 July 25, 2009 0 0 Get merch Get the regretamin mug. Buy Now — $32.95 See more merch