Resonant (8)
I believe the answer is:
sonorous
'resonant' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for sonorous that I've seen before include "Giving out a deep clear sound, like a bell say" , "Resonant" , "(Of a sound) deep, full" , "Loud and deep in timbre" , "Deep and full-sounding" .)