Coitus disturbed on account of sound (8)
I believe the answer is:
acoustic
'of sound' is the definition.
(I've seen this before)
'coitus disturbed on account' is the wordplay.
'disturbed' indicates an anagram.
'on' indicates putting letters inside.
'account' becomes 'ac'.
'coitus' anagrammed gives 'cousti'.
'cousti' placed within 'ac' is 'ACOUSTIC'.
(Other definitions for acoustic that I've seen before include "This guitar is not electric" , "Of the physical properties of sound" , "Relating to sound" , "dispensing with amps?" , "Of sound or the sense of hearing" .)