"outer part of the perianth of a flower," 1680s, from Latin calyx, from Greek kalyx "seed pod, husk, outer covering" (of a fruit, flower bud, etc.), from stem of kalyptein "to cover, conceal," from PIE root *kel- (1) "to cover, conceal, save." The Latin plural is calyces. Some sources connect the word rather with Greek kylix "drinking cup" (see chalice).
type of Italian stuffed turnover, a specialty of Naples, Italian, literally "trouser leg," so called for the resemblance.
1777, "a projecting part of a rotating machinery used to impart motion to another part," from Dutch cam "cog of a wheel," originally "comb," from Proto-Germanic *kambaz "comb," from PIE root *gembh- "tooth, nail." It is thus a cognate of English comb (n.). This might have combined with English camber "having a slight arch;" or the whole thing could be from camber. It converts regular rotary motion into irregular, fast-and-slow rotary or reciprocal motion. "The original method was by cogs or teeth fixed or cut at certain points in the circumference or disc of a wheel ..." [OED]. Cam-shaft attested from 1850.