The Collaborative International Dictionary of English v.0.48:

Chlamys \Chla"mys\, n.; pl. E. Chlamyses, L. Chlamydes. [L.,
   from Gr. ?.]
   A loose and flowing outer garment, worn by the ancient
   Greeks; a kind of cloak.
   [1913 Webster]

WordNet (r) 3.0 (2006):

chlamys
    n 1: collective term for the outer parts of a flower consisting
         of the calyx and corolla and enclosing the stamens and
         pistils [syn: perianth, chlamys, floral envelope,
         perigone, perigonium]
    2: a short mantle or cape fastened at the shoulder; worn by men
       in ancient Greece