[{"Bold_text": "noun", "List Items": ["a long, narrow, thin strip of wood, metal, etc.; slat.", "a long, flexible strip of wood or the like, used in drawing curves.", "Machinery.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. feather key feather key.", "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.", "feather key feather key.", "Building Trades.a thin strip of material inserted into the edges of two boards, acoustic tiles, etc., to make a butt joint between them; a feather.", "Mathematics, Engineering.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."]}, {"Bold_text": "verb (used with object)", "List Items": ["to provide with a spline or key.", "to provide with a keyway."]}]