Meaning

noun (ethnic slur) offensive term for a person of Irish descent

originAlternative letter-case form of Mickey (noun), from Mickey (“diminutive of the male given name Michael”, proper noun), from Mick (“diminutive of the male given name Michael”) + -ey (a variant of -y (diminutive suffix)). Noun sense 1 (“smallest distance that a computer mouse can move a cursor”) refers to the cartoon character Mickey Mouse. Noun sense 5 (“penis”), noun sense 7.1 (“Irishman”), and…

Etymology from Wiktionary, CC BY-SA 3.0