ex·o·mor·phism \ˌ ̷ ̷ ̷ ̷ˈmȯrˌfizəm\noun (-s) Etymology: International Scientific Vocabulary exo- + -morphism; originally formed as French exomorphisme : a change (as hardening or the formation of new minerals) produced in a rock mass by igneous intrusion from without : metamorphism by external contact