(of words) formed in imitation of a natural sound; "onomatopoeic words are imitative of noises"; "it was independently developed in more than one place as an onomatopoetic term"- Harry Hoijer
Literally prone to echo. Hard surfaces in listening rooms will result in a lot of high frequency reflections and a generally echoic sounding acoustic. The technical term for this is a long reverberation time. It is to be avoided if possible.