Almost look upon arbitrator to break agreement? (6)
I believe the answer is:
gazump
'break agreement?' is the definition.
(I've seen this before)
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for gazump that I've seen before include "Successfully outbid someone with already accepted offer on a house" , "Raise a house price after offer accepted" , "After agreeing a lower price with one person, accept a higher one from another" , "Offer more for a house than (an earlier bidder)" , "Raise price of property after agreeing a lower sum" .)