[1] : WordNet (r) 2.0

speak up
     v 1: speak one's opinion without fear or hesitation; "john spoke
          up at the meeting" syn: opine, animadvert, sound
          off
     2: speak louder; raise one's voice; "the audience asked the
        lecturer to please speak up"
see also:
opine animadvert sound off 

[2] : Moby Thesaurus II by Grady Ward, 1.0

66 moby thesaurus words for "speak up":
   affirm, affront, allege, announce, annunciate, appear, argue,
   assert, assever, asseverate, aver, avouch, avow, 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 out, stand for, stand on, stand up to,
   state, submit, take a stand, take the floor

Ball Up >> B Words
Ball Up, definition of term: Ball Up
ball+up_pag1.html

Bang Up >> B Words
Bang Up, definition of term: Bang Up
bang+up_pag1.html

Backed Up >> B Words
Backed Up, definition of term: Backed Up
backed+up_pag1.html

Back Up >> B Words
Back Up, definition of term: Back Up
back+up_pag1.html

Ante Up >> A Words
Ante Up, definition of term: Ante Up
ante+up_pag1.html

Act Up >> A Words
Act Up, definition of term: Act Up
act+up_pag1.html