Secure — business (4)
I believe the answer is:
firm
I believe this is a double definition.
'secure' is the first definition.
(similar in meaning)
'business' is the second definition.
(I know that firm is a type of business)
(Other definitions for firm that I've seen before include "Company; steady" , "Fixed" , "Steady sort of business organisation" , "Unyielding; company" , "decided" .)