Low female singing voice (4)
I believe the answer is:
alto
'low female singing voice' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for alto that I've seen before include "Singing voice between tenor and soprano" , "Singer's hidden inside chemical toilet" , "A singing voice or pitch" , "The highest adult male singing-voice" , "Low female singing voice" .)