ves·per·al I. \-p(ə)rəl\adjective Etymology: Late Latin vesperalis, from Latin vesper evening + -alis -al : vesper < a vesperal breeze > especially: crepuscular 2 < vesperal insects > II. noun alsoves·per·a·le\ˌvespəˈra(ˌ)lē, -rāl-, -räl-\ (-s) Etymology: French vespéral, from Late Latin vesperalis, adjective 1.: a book containing the office and music for vespers 2.: a generally colored altar cover that is used to protect the white altar cloths between ceremonies