Bulk (4)
'bulk' is the definition.
(I know that bulk can be written as mass)
This is the entire clue.
(Other definitions for mass that I've seen before include "Heap; religious service" , "13 [BULK]" , "Body of matter" , "congregate for > service" , "Church service - crowd" .)
'bulk' is the definition.
(I know that bulk can be written as volume)
This is all the clue.
(Other definitions for volume that I've seen before include "work" , "Cubic capacity" , "reading matter?" , "Three-dimensional space occupied by something" , "Intensity of sound, in a book?" .)