The Collaborative International Dictionary of English v.0.48:

Recuperate \Re*cu"per*ate\ (-?t), v. i. [imp. & p. p.
   Recuperated (-?`t?d); p. pr. & vb. n. Recuperating.] [L.
   recuperatus, p. p. of recuperare. See Recover to get
   again.]
   To recover health; to regain strength; to convalesce.
   [1913 Webster]