— gazumper , n.
/geuh zump"/ , Brit. Slang.
v.t.
1. to cheat (a house buyer) by raising the price, at the time a contract is to be signed, over the amount originally agreed upon.
n.
2. an act of gazumping.
[ 1925-30; earlier gazoomph to swindle, argot word of uncert. orig. ]