from The American Heritage® Dictionary of the English Language, 4th Edition
- In biochemistry, a symbol used as a prefix to indicate the spatial configuration of certain organic compounds with asymmetric carbon atoms. It is used if an organic compound has a configuration about an asymmetric carbon atom analogous to that of L-glyceraldehyde (the arbitrarily chosen standard), in which the hydroxy (OH) functional group is on the left side of the asymmetric carbon atom: an L-amino acid.
From l(evorotatory).(American Heritage® Dictionary of the English Language, Fourth Edition)