A toneless voice is dull and does not express any feeling. "That's most kind of him," Eleanor said tonelessly.

What is the meaning of Tonelessly?

Meaning of tonelessly in English

in a way that does not express any emotion : ... He saw me, apparently without surprise, and spoke tonelessly.

What is the synonym for toneless?

tonelessadjective. Synonyms: unintonated, aspirated, atonic, surd, pronounced with a simple breathing, without tone, without vocality, not sonant.