Contend it's a quarter past six (3)
I believe the answer is:
vie
'contend' is the definition.
(I know that contend can be written as vie)
'a quarter past six' is the wordplay.
'a quarter' becomes 'e' ().
'past' means one lot of letters go next to another.
'six' becomes 'VI' (Roman numerals).
'e' put after 'vi' is 'VIE'.
'it's' acts as a link.
(Other definitions for vie that I've seen before include "Struggle" , "I've got to contend" , "Eagerly compete" , "I've got to compete" , "Compete for something" .)