Employ Republican in hurry (4)
I believe the answer is:
hire
'employ' is the definition.
('hire' can be a synonym of 'employ')
'republican in hurry' is the wordplay.
'republican' becomes 'r' (abbreviation).
'in' indicates putting letters inside.
'hurry' becomes 'hie' ('hie' can be a synonym of 'hurry').
'r' inserted within 'hie' is 'HIRE'.
(Other definitions for hire that I've seen before include "Pay for temporary use" , "Rent, employ" , "Employ (for wages)" , "Rent or lease" , "Pay to use something" .)