Midnight mass? (6)
I believe the answer is:
gramme
'midnight mass?' is the definition.
The definition and answer can be both quantities as well as being singular nouns.
Perhaps you can see an association between them that I can't see?
'mass?' is the wordplay.
I cannot really see how this works, but
'mass?' could be 'gram' (I've seen this before) and 'gram' is located in the answer.
The remaining letters 'me' 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 gramme that I've seen before include "Arm Meg (anag)" , "One thousandth of a kilogram (Fr)" , "Small unit of mass" , "Metric unit of weight" , "Small weight" .)