blotch Play nounA large irregular patch or unsightly mark on the skin or another surface.verbCover with blotches. SYNONYMS birthmarkblemishblotdabdaubdiscolorationdoteruptionfrecklehaemangiomamarknaevuspatchpopport wine stainrashsmearsmudgespeckspecklesplashsplodgesplotchspotstainstrawberry markstreak