adj.
Pronunciation: ' tr ō - ˌ ko ̇ id, ' trä- ˌ ko ̇ id
Function: noun
Etymology: Greek trochoeid ē s like a wheel, from trochos wheel
Date: circa 1704
: the curve generated by a point on the radius of a circle or the radius extended as the circle rolls on a fixed straight line
– tro · choi · dal \ tr ō - ' ko ̇ i-d ə l, trä- \ adjective