echoic vs onomatopoeical

echoic and onomatopoeical both are adjectives.

Word	Noun	Adjective	Verb	Adverb
echoic	No	Yes	No	No
onomatopoeical	No	Yes	No	No

As adjectives, echoic and onomatopoeical are synonyms defined as:

echoic and onomatopoeical: (of words) formed in imitation of a natural sound

Other synonyms of echoic include imitative, onomatopoeic, onomatopoetic.

echoic (adjective)	onomatopoeical (adjective)
(of words) formed in imitation of a natural sound	(of words) formed in imitation of a natural sound
like or characteristic of an echo