'anechoic' originates from Greek, specifically the prefix 'an-' meaning 'without' and 'echo' meaning 'sound reflection', with the suffix '-ic' forming an adjective.

'anechoic' was formed in the early 20th century from the combination of Greek elements and the English word 'echo', and eventually became the modern English word 'anechoic'.

Initially, it meant 'without echo', and over time it evolved into its current technical meaning of 'designed to absorb sound or electromagnetic reflections'.