'allomorph' originates from Greek, specifically the word 'allomorphos,' where 'allo-' meant 'other' and 'morphē' meant 'form.'

'allomorphos' transformed into the English word 'allomorph' through the influence of linguistic studies in the 20th century.

Initially, it meant 'other form,' and over time it evolved into its current meaning of 'variant form of a morpheme.'