VERB (3)

1. ask humbly (for something);
- Example: "He supplicated the King for clemency"

2. make a humble, earnest petition;
- Example: "supplicate for permission"

3. ask for humbly or earnestly, as in prayer;
- Example: "supplicate God's blessing"

The Collaborative International Dictionary of English v.0.48:

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.
      [1913 Webster]

   2. To address in prayer; to entreat as a supplicant; as, to
      supplicate the Deity.
      [1913 Webster]

   Syn: To beseech; entreat; beg; petition; implore; importune;
        solicit; crave. See Beseech.
        [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Supplicate \Sup"pli*cate\, v. i.
   To make petition with earnestness and submission; to implore.
   [1913 Webster]

         A man can not brook to supplicate or beg. --Bacon.
   [1913 Webster]

WordNet (r) 3.0 (2006):

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"