The Collaborative International Dictionary of English v.0.48:

Regain \Re*gain"\ (r?*g?n"), v. t. [Pref. re- + gain: cf. F.
   regagner.]
   To gain anew; to get again; to recover, as what has escaped
   or been lost; to reach again.
   [1913 Webster]

   Syn: To recover; reobtain; repossess; retrieve.
        [1913 Webster]

WordNet (r) 3.0 (2006):

regain
    v 1: get or find back; recover the use of; "She regained control
         of herself"; "She found her voice and replied quickly"
         [syn: recover, retrieve, find, regain]
    2: come upon after searching; find the location of something
       that was missed or lost; "Did you find your glasses?"; "I
       cannot find my gloves!" [syn: find, regain] [ant: lose]

Moby Thesaurus II by Grady Ward, 1.0:

28 Moby Thesaurus words for "regain":
   achieve, attain, compass, gain, get back, ransom, reach, recapture,
   reclaim, recoup, recover, recruit, recuperate, redeem, renew,
   renovate, reoccupy, replevin, replevy, repossess, restore, resume,
   retake, retrieve, revindicate, revive, save, take back