The Collaborative International Dictionary of English v.0.48:

Cot \Cot\ (k[o^]t), n. [AS. cot cottage, bedchamber; or cf. OF.
   coite, F. couette (E. quilt), LL. cottum, cottus, mattress.
   See Cot a cottage.]
   A sleeping place of limited size; a little bed; a cradle; a
   piece of canvas extended by a frame, used as a bed. [Written
   also cott.]
   [1913 Webster]