1852, in chemistry, back-formation from isomeric. A compound identical or nearly so in composition and molecular weight with another, but having different properties.
Entries linking to isomer
isomeric adj.
"pertaining to or characterized by isomerism," 1831, from German isomerisch (Berzelius, 1831, in a paper on the "Composition of the Tartaric and Paratartaric Racemic Acids"), from Greek isomeres "sharing equality, having equal parts or shares," from iso- "equal" (see iso-) + meros "part, share" (from PIE root *(s)mer- (2) "to get a share of something"). Isomerous is from 1845 in botany, 1840 in chemistry.
*(s)mer- 2
Proto-Indo-European root meaning "to get a share of something."
It forms all or part of: demerit; emeritus; isomer; isomeric; meretricious; merism; meristem; merit; meritorious; mero-; monomer; Moira; polymer; turmeric.
It is the hypothetical source of/evidence for its existence is provided by: Greek meros "part, lot," moira "share, fate," moros "fate, destiny, doom;" Hittite mark "to divide" a sacrifice; Latin merere, meriri "to earn, deserve, acquire, gain."