Greenmail

[green-meyl] /ˈgrinˌmeɪl/

noun, Stock Exchange.
1.
the practice of buying a large block of a company’s stock in order to force a rise in stock prices or an offer by the company to repurchase that block of stock at an inflated price to thwart a possible takeover bid.
/ˈɡriːnˌmeɪl/
noun
1.
(esp in the US) the practice of a company buying sufficient shares in another company to threaten takeover and making a quick profit as a result of the threatened company buying back its shares at a higher price

noun

The buying, at a premium price, of the stock holdings of someone who is threatening to take over a company, in order to induce the person to cease the attempt: The most cited recent case of greenmail occurred this spring and summer as Walt Disney Productions fought to escape a takeover/ But Wall Street analysts agreed that CBS was unlikely to consider such action, since it amounts to ”greenmail”

[1983+; modeled on blackmail]