Entry 1 sense Webster, 1913 Lumpy /lŭm'-pē/ · Lump·y · IPA /ˈlʌmpi/ 01 a. Full of lumps, or small compact masses; as, a lumpy bed; a lumpy batch of dough. 1. Full of lumps, or small compact masses; as, a lumpy bed; a lumpy batch of dough.