1. Express or utter with a hiss
   "The villain sizzed his threats";
   - hiss, siss [US, informal], sibilate
    
2. Make a sharp hissing sound, as if to show disapproval
   "The hot iron sizzed as it touched the wet cloth";
   - hiss, siss [US, informal], sibilate

Derived forms: sizzing, sizzes, sizzed

Type of: emit, let loose, let out, mouth, speak, talk, utter, verbalise [Brit], verbalize