/meuh tam"euh riz'euhm/ , n.
1. Zool.
a. division into metameres, the developmental process of somite formation.
b. existence in a metameric state.
2. Chem. isomerism resulting from the attachment of different groups to the same atom, as C 2 H 5 NHC 2 H 5 and CH 3 NHC 3 H 7 .
[ 1840-50; (in def. 1) METAMERE + -ISM; (in def. 2) META- + (ISO)MERISM ]