Entry 1 sense Webster, 1913 Gallnut · Gall·nut · IPA 01 n. A round gall produced on the leaves and shoots of various species of the oak tree. See Gall, and Nutgall. 1. A round gall produced on the leaves and shoots of various species of the oak tree. See Gall, and Nutgall.(Zool.) See: Gall, Nutgall