Contend it's a quarter after six (3)
I believe the answer is:
vie
'contend' is the definition.
(I know that contend can be written as vie)
'a quarter after six' is the wordplay.
'a quarter' becomes 'e' ().
'after' is a charade indicator (letters next to each other).
'six' becomes 'VI' (Roman numerals).
'e' put after 'vi' is 'VIE'.
'it's' is the link.
(Other definitions for vie that I've seen before include "I've got to compete" , "Contend for superiority" , "Compete (with others)" , "Compete for something" , "contest" .)