From The Collaborative International Dictionary of English v.0.48:
Cyme \Cyme\ (s?m), n. [L. cyma the young sprount of a cabbage,
fr. Gr. ???, prop., anything swollen, hence also cyme, wave,
fr. ??? to be pregnant.] (Bot.)
A flattish or convex flower cluster, of the centrifugal or
determinate type, differing from a corymb chiefly in the
order of the opening of the blossoms.
[1913 Webster]