Rough number (5)
I believe the answer is:
gross
I believe this is a double definition.
'rough' is the first definition.
(thesaurus)
'number' is the second definition.
(gross is a kind of whole number)
(Other definitions for gross that I've seen before include "Vulgar, coarse" , "figure well over a ton" , "exclamation of disgust" , "Arrant" , "Earn" .)