1. a combining form with the meanings “stretching,” “tension,” “tone,” used in the formation of compound words: tonometer.

Origin of tono-

< Greek tón(os) (see tone) + -o- Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

tono- in Medicine


  1. Tone; tension; pressure:tonography.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.