Pro inspires university rowing crew (4)
I believe the answer is:
four
'rowing crew' is the definition.
(crew of four rowers)
'pro inspires university' is the wordplay.
'pro' becomes 'for' (I've seen this before).
'inspires' means one lot of letters goes inside another (inspire means to breathe in).
'university' becomes 'U' (abbreviation for university).
'for' enclosing 'u' is 'FOUR'.
(Other definitions for four that I've seen before include "teatime?" , "How many Horsemen of the Apocalypse?" , "Number of Eliot Quartets" , "Cube root of sixty four" , "Petit --, fancy biscuit" .)