The Collaborative International Dictionary of English v.0.48:

Eloquent \El"o*quent\, a. [F. ['e]loquent, L. eloquens, -entis,
   p. pr. of eloqui to speak out, declaim; e + loqui to speak.
   See Loquacious.]
   1. Having the power of expressing strong emotions or forcible
      arguments in an elevated, impassioned, and effective
      manner; as, an eloquent orator or preacher.
      [1913 Webster]

            O Death, all-eloquent! You only prove
            What dust we dote on when 't is man we love. --Pope.
      [1913 Webster]

   2. Adapted to express strong emotion or to state facts
      arguments with fluency and power; as, an eloquent address
      or statement; an eloquent appeal to a jury.
      [1913 Webster]

WordNet (r) 3.0 (2006):

eloquent
    adj 1: expressing yourself readily, clearly, effectively; "able
           to dazzle with his facile tongue"; "silver speech" [syn:
           eloquent, facile, fluent, silver, silver-
           tongued, smooth-spoken]