Against leaving barge in Oxford? (4)
I believe the answer is:
shoe
'oxford?' is the definition.
(oxford is a kind of shoe)
'against leaving barge' is the wordplay.
'against' becomes 'v' (abbreviation for 'versus').
'leaving' is a deletion indicator.
'barge' becomes 'shove' (I've seen this before).
'shove' with 'v' removed is 'SHOE'.
'in' acts as a link.
(Other definitions for shoe that I've seen before include "One of a pair to wear" , "Hose for the foot?" , "Last product" , "One of the things racehorse needs" , "Covering for foot" .)