1. Make less strong or intense; soften
   "Tone down that aggressive letter";
   - moderate, tame
    
2. Deaden (a sound or noise), especially by wrapping
   "They toned down the speakers with foam padding";
   - muffle, mute, dull, damp, dampen

Derived forms: toning down, toned down, tones down

Type of: alter, change, modify, soften