Sailing boat? At university? Sauce! (7)
I believe the answer is:
ketchup
'sauce' is the definition.
(ketchup is a type of sauce)
'sailing boat? at university?' is the wordplay.
'sailing boat?' becomes 'ketch' (type of sailing boat).
'at university?' becomes 'up' ('up' can mean studying at university).
'ketch'+'up'='KETCHUP'
(Other definitions for ketchup that I've seen before include "Red sauce" , "Piquant sauce, often tomato based" , "Condiment" , "Sauce made largely of tomatoes" , "Relish" .)