(linguistics) any of various acoustically different forms of the same phoneme

Wikipedia Word definitions in Wikipedia
In phonology , an allophone (; from the , állos , "other" and φωνή, phōnē , "voice, sound") is one of a set of multiple possible spoken sounds (or phones ) or signs used to pronounce a single phoneme in a particular language. For example, (as in pin ) and ...

WordNet Word definitions in WordNet
n. (linguistics) any of various acoustically different forms of the same phoneme

Wiktionary Word definitions in Wiktionary
n. 1 (context phonetics English) Any of two or more alternative pronunciations for a phoneme. 2 (context Canada English) A person whose mother tongue is neither English nor French.

The Collaborative International Dictionary Word definitions in The Collaborative International Dictionary
allophone \allophone\ n. any one of two or more speech sounds that considered variants of the same phoneme. For example, the p sounds of pin and spin are allophones of p; and the t sounds of toe stop and catnip are allophones of t.