<p><strong>Noun:</strong></p><ul><li>A long, narrow, thin strip of wood, metal, etc.; slat.</li><li>A long, flexible strip of wood or the like, used in drawing curves.</li><li>Any of a series of uniformly spaced ridges on a shaft, parallel to its axis and fitting inside corresponding grooves in the hub of a gear, etc., to transmit torque.</li><li>A thin strip of material inserted into the edges of two boards, acoustic tiles, etc., to make a butt joint between them; a feather.</li><li>A function that has specified values at a finite number of points and consists of segments of polynomial functions joined smoothly at these points, enabling it to be used for approximation and interpolation of functions.</li></ul><p><strong>Verb:</strong></p><ul><li>To provide with a spline or key.</li><li>To provide with a keyway.</li></ul>