Search Result for "meso-": 

The Collaborative International Dictionary of English v.0.48:

Meso- \Mes"o-\, Mes- \Mes-\ [Gr. me`sos in the middle.] 1. A combining form denoting in the middle, intermediate. [1913 Webster] 2. specif. (Chem.), Denoting a type of hydrocarbons which are regarded as methenyl derivatives. Also used adjectively. [1913 Webster] 3. (Chem.) Optically inactive due to compensating optical activity at two or more asymmetric centers, often due to a plane of symmetry within the molecular structure; as, meso-tartaric acid. [PJC] 4. Attached to a carbon atom located between two hereoatoms in a heterocyclic ring. [PJC]