Source : Webster's Revised Unabridged Dictionary (1913)

Supplicate \Sup"pli*cate\, v. i.
   To make petition with earnestness and submission; to implore.

         A man can not brook to supplicate or beg. --Bacon.

Supplicate \Sup"pli*cate\, v. t. [imp. & p. p. {Supplicated}; p.
   pr. & vb. n. {Supplicating}.] [L. supplicatus, p. p. of
   supplicare to supplicate; of uncertain origin, cf. supplex,
   supplicis, humbly begging or entreating; perhaps fr. sub
   under + a word akin to placare to reconcile, appease (cf.
   {Placable}), or fr. sub under + plicare to fold, whence the
   idea of bending the knees (cf. {Ply}, v. t.). Cf. {Supple}.]
   1. To entreat for; to seek by earnest prayer; to ask for
      earnestly and humbly; as, to supplicate blessings on
      Christian efforts to spread the gospel.

   2. To address in prayer; to entreat as a supplicant; as, to
      supplicate the Deity.

   Syn: To beseech; entreat; beg; petition; implore; importune;
        solicit; crave. See {Beseech}.

Source : WordNet®

supplicate
     v 1: ask humbly (for something); "He supplicated the King for
          clemency"
     2: make a humble, earnest petition; "supplicate for permission"
     3: ask for humbly or earnestly, as in prayer; "supplicate God's
        blessing"