noun
cycloid
A mathematical curve traced by a point on the rim of a circle rolling along a straight line. Used in geometry and mechanics.
サイクロイド曲線は、円が直線上を転がるときに円周上の一点が描く軌跡です。
A cycloid curve is the locus traced by a point on the circumference of a circle as it rolls along a straight line.
Borrowed from English 'cycloid', ultimately from Greek 'kuklos' (circle) + '-oeidēs' (like).