any of two or more different forms of the same chemical compound.
2.
Linguistics. one of the alternate contextually determined phonological shapes of a morpheme, as en in oxen, which is an allomorph of the English plural morpheme.
(linguistics) any of the phonological representations of a single morpheme. For example, the final (s) and (z) sounds of bets and beds are allomorphs of the English noun-plural morpheme
2.
any of two or more different crystalline forms of a chemical compound, such as a mineral