Constant company (4)
I believe the answer is:
firm
I believe this is a double definition.
'constant' is the first definition.
(I've seen this before)
'company' is the second definition.
(firm can mean a company or business)
(Other definitions for firm that I've seen before include "Resolute kind of business" , "solid structure" , "Unyielding; company" , "Steady commercial organisation?" , "decided" .)