calyx (n.) Look up calyx at Dictionary.com
1680s, from Latin calyx, from Greek kalyx "seed pod, husk, outer covering" (of a fruit, flower bud, etc.), from root of kalyptein "to cover, conceal," from PIE root *kel- (1) "to cover, conceal, save." The proper plural is calyces. Some sources connect the word rather with Greek kylix "drinking cup."