It could deceive in case voice, male, stifles hum (5,6)
I believe the answer is:
false bottom
'it could deceive in case voice male stifles hum' is the definition.
The definition suggests a singular noun which matches the answer.
'it could deceive in case voice male stifles hum' is the wordplay.
I cannot really understand how this works, but
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is present in the answer.
'male' could be 'tom' (tom can mean a male cat) and 'tom' is present in the answer.
'hum' could be 'bo' (body odour - hum can mean a smell) and 'bo' is present in the answer.
The remaining letters 'false' is a valid word which might be clued in a way I don't see.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for false bottom that I've seen before include "Secret compartment (in a briefcase?)" , "Partition in case, creating a concealed space" , "Hiding place in a suitcase, perhaps" , "Secret compartment in a suitcase, for example" .)