Phoneme (noun)

1. The smallest unit of sound in a word that can change the word's meaning.
2. A linguistic unit of sound that distinguishes one word from another in a particular language.

Origin:

From the greek "phōnēma" meaning "a sound, a voice".

Examples:

1. In English, the "p" sound and the "b" sound are separate phonemes.
2. The phoneme inventory of a language will vary depending on the language.
3. The child is learning to distinguish between different phonemes in speech.
4. The phoneme is the basic unit of sound in language.
5. The phoneme is a linguistic unit of sound which is the smallest unit of sound that makes a difference in word meaning.