WordNet (r) 3.0 (2006):

speak out
    v 1: express one's opinion openly and without fear or
         hesitation; "John spoke up at the meeting" [syn: opine,
         speak up, speak out, animadvert, sound off]

Moby Thesaurus II by Grady Ward, 1.0:

68 Moby Thesaurus words for "speak out":
   affirm, affront, allege, announce, annunciate, appear, argue,
   assert, assever, asseverate, aver, avouch, avow, be frank, beard,
   bell the cat, bite the bullet, brave, brazen, brazen out,
   break silence, come forth, confront, contend, declare, enunciate,
   express, face, face the music, face up, face up to, front, have,
   have no secrets, hold, insist, issue a manifesto, lay down,
   maintain, manifesto, materialize, meet, meet boldly, meet head-on,
   open up, pipe up, predicate, proclaim, profess, pronounce, protest,
   put, put it, run the gauntlet, say, say out, set at defiance,
   set down, speak, speak plainly, speak up, stand for, stand on,
   stand up to, state, submit, take a stand, take the floor