Search Result for "toneless": 
Wordnet 3.0

ADJECTIVE (1)

1. lacking in tone or expression;
- Example: "his toneless mechanical voice"



The Collaborative International Dictionary of English v.0.48:

Toneless \Tone"less\, a.
   Having no tone; unmusical.
   [1913 Webster] Tong


WordNet (r) 3.0 (2006):

toneless
    adj 1: lacking in tone or expression; "his toneless mechanical
           voice" [ant: toned]