nutn.[OE. nute, note, AS. hnutu; akin to D. noot, G. nuss, OHG. nuz, Icel. hnot, Sw. nt, Dan. nd.]()1. (Bot.) The fruit of certain trees and shrubs (as of the almond, walnut, hickory, beech, filbert, etc.), consisting of a hard and indehiscent shell inclosing a kernel.()2. A perforated block (usually a small piece of metal), provided with an internal or female screw thread, used on a bolt, or screw, for tightening or holding something, or for transmitting motion. See Illust. of 1st Bolt.()3. The tumbler of a gunlock.(Knight.)4. (Naut.) A projection on each side of the shank of an anchor, to secure the stock in place.()5. Testicles.()Check nut, Jam nut, Lock nut, a nut which is screwed up tightly against another nut on the same bolt or screw, in order to prevent accidental unscrewing of the first nut. -- Nut buoy. See under Buoy. -- Nut coal, screened coal of a size smaller than stove coal and larger than pea coal; -- called also chestnut coal. -- Nut crab (Zol.), any leucosoid crab of the genus Ebalia as, Ebalia tuberosa of Europe. -- Nut grass (Bot.), See nut grass in the vocabulary. -- Nut lock, a device, as a metal plate bent up at the corners, to prevent a nut from becoming unscrewed, as by jarring. -- Nut pine. (Bot.) See under Pine. -- Nut rush (Bot.), a genus of cyperaceous plants (Scleria) having a hard bony achene. Several species are found in the United States and many more in tropical regions. -- Nut tree, a tree that bears nuts. -- Nut weevil (Zol.), any species of weevils of the genus Balaninus and other allied genera, which in the larval state live in nuts.()v. i. To gather nuts.()