-tonia

  1. a combining form with the meaning “muscle tension, nerve tension,” as specified by the initial element (hypertonia); used also in the formation of words that denote more generally a personality type or personality disorder (catatonia; somatotonia).

Origin of -tonia

see origin at tone, -ia
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

-tonia in Medicine

-tonia

suff.
  1. Degree or state of tonicity:myotonia.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.