'echoic' originates from Greek, specifically the word 'ēkhō' (Greek: ἠχώ), where 'ēkhō' meant 'sound, echo', combined with the suffix '-ic' from Greek '-ikos' meaning 'pertaining to'.

'ēkhō' entered Latin and Old French as 'echo' and then Middle English as 'echo'; the adjective form 'echoic' was formed in English by adding the suffix '-ic' to denote 'pertaining to an echo'.

Initially, it meant 'of or relating to an echo'; over time it broadened to include 'imitative of sounds (onomatopoeic)' and specialized senses such as 'relating to echoic memory' in psychology.