Some say it's gross (5)
I believe the answer is:
total
'gross' is the definition.
(I know that gross can be written as total)
'some say it's' is the wordplay.
I cannot really see how this works, but
'some' could be 'a' and 'a' is present in the answer.
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is present in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for total that I've seen before include "Absolute; sum" , "energy provider" , "Comprising the whole" , "Full, entire amount" , "Complete, absolute" .)