On a trip before spring event (4,4)
I believe the answer is:
high jump
'event' is the definition.
(high jump is a kind of event)
'on a trip before spring' is the wordplay.
'on a trip' becomes 'high' (I've seen this before).
'before' means one lot of letters go next to another.
'spring' becomes 'jump' ('jump' can be a synonym of 'spring'**).
'high'+'jump'='HIGH JUMP'
(Other definitions for high jump that I've seen before include "Athletic event" , "A severe reprimand" , "Fosbury's event" , "Lofty leap as drastic punishment" , "bar activity?" .)