Denoting a mixture of optically active compounds that is itself optically inactive, being composed of an equal number of dextro- and levorotatory substances, which are separable. Those compounds internally compensated ( i.e., having an internal plane of symmetry) and therefore not separable into d and l (or + and −) forms, are termed “meso.”
* * *
ra·ce·mic rā-'sē-mik, rə- adj of, relating to, or constituting a compound or mixture that is composed of equal amounts of dextrorotatory and levorotatory forms of the same compound and is optically inactive compare DL-
* * *
ra·ce·mic (ra-seґmik) made up of two enantiomorphic isomers and therefore optically inactive.Medical dictionary. 2011.