The Collaborative International Dictionary of English v.0.48:

Implore \Im*plore"\, v. t. [imp. & p. p. Implored; p. pr. &
   vb. n. Imploring.] [L. implorare; pref. im- in + plorare to
   cry aloud. See Deplore.]
   To call upon, or for, in supplication; to beseech; to pray
   to, or for, earnestly; to petition with urgency; to entreat;
   to beg; -- followed directly by the word expressing the thing
   sought, or the person from whom it is sought.
   [1913 Webster]

         Imploring all the gods that reign above. --Pope.
   [1913 Webster]

         I kneel, and then implore her blessing.  --Shak.

   Syn: To beseech; supplicate; crave; entreat; beg; solicit;
        petition; prey; request; adjure. See Beseech.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Implore \Im*plore"\, v. i.
   To entreat; to beg; to prey.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Implore \Im*plore"\, n.
   Imploration. [Obs.] --Spencer.
   [1913 Webster]

WordNet (r) 3.0 (2006):

implore
    v 1: call upon in supplication; entreat; "I beg you to stop!"
         [syn: beg, implore, pray]

Moby Thesaurus II by Grady Ward, 1.0:

35 Moby Thesaurus words for "implore":
   adjure, appeal, appeal to, beg, beseech, call for help, call on,
   call upon, clamor for, commune with God, conjure, crave, cry for,
   cry on, cry to, entreat, give thanks, impetrate, importune,
   imprecate, invoke, kneel to, make supplication, obtest,
   offer a prayer, petition, plead, plead for, pray, pray over,
   recite the rosary, return thanks, run to, say grace, supplicate