the.com/phoneme

means The smallest unit of sound in a language that distinguishes one word from another, like the 'b' versus 'p' sound that separates 'bat' from 'pat'.

from Built in the early 1900s from Greek phōnēma, meaning 'sound' or 'that which is spoken,' itself from phōnē, 'voice' or 'sound.' Linguists reached for that Greek root — the same one behind 'phone' and 'telephone' — to name a brand-new idea in the young science of linguistics: that languages run on a small, countable set of meaningful sound-units, not an endless blur of noise.