M0239400 (mĕz′ə-thôr′ăks′, mĕs′-)n.pl.mes·o·tho·rax·es or mes·o·tho·ra·ces(-thôr′ə-sēz′) The middle of the three divisions of the thorax of an insect, bearing the middle pair of legs and the first pair of wings.mes′o·tho·rac′ic(-thə-răs′ĭk) adj.EncyclopediaSeemesothorax