gazump - meaning and definition. What is gazump
Diclib.com
Online Dictionary

What (who) is gazump - definition

OCCURS WHEN A SELLER (ESPECIALLY OF PROPERTY) ACCEPTS AN ORAL OFFER OF THE ASKING PRICE FROM ONE POTENTIAL BUYER, BUT THEN ACCEPTS A HIGHER OFFER FROM SOMEONE ELSE
Gazump; Gazundering

gazump         
British. To offer more for a house than another has already offered and had accepted. In US, this is not allowed - in UK, it is
I've been gazumped on the house I made an offer on.
gazump         
[g?'z?mp]
¦ verb Brit. informal make a higher offer for a house than (someone whose offer has already been accepted) and thus succeed in acquiring the property.
Derivatives
gazumper noun
Origin
1920s (in sense 'swindle'): from Yiddish gezumph 'overcharge'.
gazump         
(gazumps, gazumping, gazumped)
If you are gazumped by someone, they agree to sell their house to you, but then sell it to someone else who offers to pay a higher price. (BRIT INFORMAL)
In France you cannot be gazumped...
VERB: usu passive, be V-ed
gazumping
During the 1980s property boom, gazumping was common.
N-UNCOUNT

Wikipedia

Gazumping

Gazumping occurs when a seller (especially of property) accepts a verbal offer (a promise to purchase) on the property from one potential buyer, but then accepts a higher offer from someone else. It can also refer to the seller raising the asking price or asking for more money at the last minute, after previously verbally agreeing to a lower one. In either case, the original buyer is left in a bad situation, and either has to offer a higher price or lose the purchase. The term gazumping is most commonly used in the United Kingdom and Ireland, although similar practices can be found in some other jurisdictions.

Examples of use of gazump
1. Hicks, who also owns the Texas Rangers baseball team, joined forces with Gillett to gazump rival bidders Dubai International Capital last week.