mesotartaric \mes`o*tar*tar"ic\, a. [Meso- + tartaric.] (Chem.)
Pertaining to, or designating, an acid called also {inactive
tartaric acid}. It is an optically inactive stereoisomer of
tartaric acid due to internal compensation of the rotatory
activity of the two asymmetric centers; it has a plane of
symmetry in the molecule.
[1913 Webster +PJC]