allomorph

any of two or more different forms of the same chemical compound.

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.: Compare morph.

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

any of two or more different crystalline forms of a chemical compound, such as a mineral