/ Dictionary / Index M mesothorax: Meaning and Definition of Find definitions for: mes•o•tho•rax Pronunciation: (mez"u-thôr'aks, -thōr'-, mes"-, mē"zu-, -su-), [key] — pl. -tho•rax•es, -tho•ra•ces the middle segment of the three divisions of the thorax of an insect, bearing the second pair of legs and the first pair of wings. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. mesothelium mesotron Related Content Daily Word Quiz: vertigo Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language