mesic1 Syllabification: (mes·ic)Pronunciation: /ˈmezik, ˈmē-/Definition of mesic adjective Ecology (of an environment or habitat) containing a moderate amount of moisture. Compare with hydric and xeric.Origin: 1920s: from Greek mesos 'middle' + -icmesic in other Oxford dictionaries Definition of mesic in the British & World English dictionary