The Collaborative International Dictionary of English v.0.48:

Supplicant \Sup"pli*cant\, a. [L. supplicans, p. pr. See
   Supplicate, and cf. Suppliant.]
   Entreating; asking submissively. --Shak. --
   Sup"pli*cant*ly, adv.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Supplicant \Sup"pli*cant\, n.
   One who supplicates; a suppliant.
   [1913 Webster]

         The wise supplicant . . . left the event to God.
                                                  --Rogers.
   [1913 Webster]

WordNet (r) 3.0 (2006):

supplicant
    adj 1: humbly entreating; "a suppliant sinner seeking
           forgiveness" [syn: suppliant, supplicant,
           supplicatory]
    n 1: someone who prays to God [syn: prayer, supplicant]
    2: one praying humbly for something; "a suppliant for her
       favors" [syn: petitioner, suppliant, supplicant,
       requester]

Moby Thesaurus II by Grady Ward, 1.0:

23 Moby Thesaurus words for "supplicant":
   appellant, applicant, asker, aspirant, beggar, begging, beseecher,
   beseeching, entreating, imploring, importunate, mendicant,
   petitioner, plaintiff, pleader, prayer, praying, solicitous,
   suitor, suppliant, supplicating, supplicator, supplicatory