I. ˈtrōˌkȯid noun
( -s )
Etymology: Greek trochoeidēs round like a wheel, circular, from troch- + -oeidēs -oid
1. : the curve generated by a point on the radius of a circle as the circle rolls on a fixed straight line — compare cycloid
2. or trochoid joint : pivot joint
II. adjective
Etymology: in sense 1, from New Latin Trochus + English -oid; in sense 2, from trochoid (I)
1.
a. : trochiform
b. : of or relating to a top shell
2. : admitting of rotation on a longitudinal axis