n. A folding or doubling of a string, lace, cord, chain, etc., or a short piece doubled and secured to something at each end.n. Something resembling a loop, as the bend of a river; a link; a crook.n. Specifically—n. In crochet, knitting, and similar kinds of fancy work, same as stitch.n. A hinge of a door.n. In railroad and telegraph systems, a branch line leaving the main line at any point and joining it again at some other point; a looping line, as a branch wire carried over to a side station and back.n. In the theory of Riemann's surfaces, a line running from any point to a branchpoint, then around that branch-point in an infinitesimal circle, and back to the original point by the same path.n. A part of a curve limited by a crunode.n. The ear of a vessel, as a stoneware jar, when approximately of the form of a half-ring projecting from the side or lip.n. In gunnery, a small fron ring in the barrel of a gun.n. The small ring at the tip of a fishing-rod through which the line passes.n. In anatomy, a looped vessel or fiber; especially, a nerve-loop.n. In brachiopods, the folding of the brachial appendages.n. In acoustics, the part of a vibrating musical string (see sonometer), or, as in an organ-pipe, of a column of air, where the amplitude of vibration is at its maximum. See node.n. In mech., a slotted bar or ring at the side of any piece of machinery, designed to limit or control the movement of another part.n. A knot or bur, often of great size, occurring on walnut, maple, oak, and some other trees.n. A small magnifying-glass.To form into a loop or loops: as, to loop a cord.To fasten or secure with a loop or loops: as, to loop up a curtain.To furnish with a loop or loops: as, to loop a cloak.To form a loop.To move, as the larvæ of certain moths, by forming loops.n. A narrow window; any small, narrow aperture; specifically, in medieval fortification, a small aperture for observing the enemy, for the discharge of arrows or ordnance, or to admit light; a loophole.n. A gap in the paling of a park, made for the convenience of the deer.n. A removable fence-panel made of parallel wooden bars, generally united by transverse braces or crosspieces, used as a substitute for an ordinary fence-gate.n. See loupe.n. n. In physical, that region, in a standing wave system, for which the amplitude of vibration is a maximum: opposed to node, which is the region of zero amplitude.