Entry 1 sense Webster, 1913 litterbug /(lĭt"tẽr*bŭg)/ · lit·ter·bug · IPA /ˈlɪtɚˌbʌɡ/ 01 n. a person who litters public places with refuse. 1. a person who litters public places with refuse. Syn. litterer, litter lout.