Main Entry: en·an·tio·mer Pronunciation: in-'ant-E-&-m&r Function: noun : either of a pair of chemical compounds whose molecularstructures have a mirror-image relationship to each other called also optical antipode —en·an·tio·mer·ic/-"ant-E-&-'mer-ik/adjective —en·an·tio·mer·i·cal·ly/-i-k(&-)lE/adverb