What does the word monotone mean?

Usage examples for monotone

  1. " I told you in my letters that I liked it," she replied in an expressionless monotone. – Not Pretty, But Precious by John Hay, et al.
  2. She was staring straight into the fire and speaking in a dull monotone, with no spring in her voice. – A Romance of Wastdale by A. E. W. (Alfred Edward Woodley) Mason