Gazumping.

I learned a new word just now. Seeing it in a headline — "Clooneys gazumped me for French vineyard, rival buyer says" (London Times) — I thought it might be a made-up word. But the OED identifies it as a slang word that goes back to 1928:

1928 Daily Express 19 Dec. 2/7 ‘Gazoomphing the sarker’ is a method of parting a rich man from his money. An article is auctioned over and over again, and the money bid each time is added to it. ...

1934 P. Allingham Cheapjack xv. 189 Grafters speak a language comprised of every possible type of slang... Quite a number of words are Yiddish. These include ‘gezumph’, which means to cheat or to overcharge. 

1971 Guardian 8 Nov. 13/2 ‘Gazumping’—a system of profiteering by double selling and pushing prices up—is creeping into the property market... The word is car trade slang for selling to one buyer and then, as values rise, to a second buyer.

It means "To swindle; spec. to act improperly in the sale of houses, etc."

As the Times article notes, gazumping violates French law.

Guy Azzari, the buyer’s lawyer, alleges his client had agreed a price of €6 million (£5.14 million) in August for the six-bedroom 18th-century bastide set in 172 hectares that include woodland, an olive grove, a vineyard and an ornamental lake.

The seller is accused of raising the price after the offer was accepted, and it says here that there's "no suggestion that the Clooneys did anything unlawful, or indeed knew of the alleged gazumping." 

"Gazumping" should not be confused with "galumphing," which is one of the many words coined by Lewis Carroll in "Jabberwocky." "Galumphing" is clumsy, heavy walking. And we know the dashing George and the lovely Amal would never do that.

He left it dead, and with its head/He went galumphing back....

That's got nothing to do with celebs attaching their names to the trendiness of rosé wine.