1. Express an opinion, especially publicly or critically
   "He sounded off about the new policy at the meeting";
   - opine, speak up, speak out, animadvert
    
2. Express complaints, discontent, displeasure, or unhappiness
   "My mother sounds off all day";
   - complain, kick [informal], plain [archaic], kvetch [N. Amer, informal], moan
    
3. (music) start playing
   "The band sounded off with their signature song";
   - strike up

Derived forms: sounded off, sounds off, sounding off

See also: sound

Type of: declare, express, give tongue to, play, pronounce, utter, verbalise [Brit], verbalize