mesomorphic /ˌmɛzəˈmɔɹfɪk/ adjective2 •Of or pertaining to a mesomorph.For instance, compared to the typical ectomorphic or endomorphic child, the mesomorphic boy or girl may have more energy and a greater motivation for vigorous play with peers. — 1993 •Of or pertaining to phases of matter intermediate between solid and liquid; of or pertaining to liquid crystals.Changes in the chemical constitution of a mesomorphic compound may therefore radically alter the mesomorphic properties and thermal stabilities. — 1958 formsmore mesomorphic · most mesomorphic