Enantiomer
WordNet
noun
(1) Either one of a pair of compounds (crystals or molecules) that are mirror images on each other but are not identical
WiktionaryText
Noun
- One of a pair of stereoisomers that is the mirror image of the other, but may not be superimposed on this other stereoisomer. Almost always, a pair of enantiomers contain at least one chiral centre, and a sample of either enantiomer will be optically active.