ar·cu·a·tion \ˌ ̷ ̷ ̷ ̷ˈwāshən\noun (-s) Etymology: Latin arcuation-, arcuatio arch, from arcuatus + -ion-, -io -ion 1.: an arching or curving : incurvation < the arcuation of the face of a cliff > 2.architecture: the employment of arches; also: a system of arches