Physicist's amount (4)
I believe the answer is:
mass
(Other definitions for mass that I've seen before include "Heap; religious service" , "seasonal midnight service?" , "Religious ceremony" , "Large amount, body" , "The proletariat" .)
I believe the answer is:
mass
(Other definitions for mass that I've seen before include "Heap; religious service" , "seasonal midnight service?" , "Religious ceremony" , "Large amount, body" , "The proletariat" .)