Meaning of diastereomer

di•a•ster•e•o•mer

Pronunciation: (dī"u-ster'ē u mur, -stēr'-), [key]
— n. Chem.
  1. either of a pair of stereoisomers that are not mirror images of each other. Also calledCf. enantiomer.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.