Entry 1 sense Webster, 1913 Nanism /(nā"nĭz'm; năn"ĭz'm)/ · Na·nism · IPA 01 n. The condition of being abnormally small in stature; dwarfism; dwarfishness; -- opposed to gigantism. 1. The condition of being abnormally small in stature; dwarfism; dwarfishness; -- opposed to gigantism.