Real Dictionary

buy out
phrasal verb: If you buy someone out, you buy their share of something such as a company or piece of property that you previously owned together.

buy out in American English
to buy all the stock, business rights, etc. of
to secure all of (an owner or partner's) share or interest in an enterprise

buy out in British English
to purchase the ownership, controlling interest, shares, etc, of (a company, etc)
noun: the purchase of a company, esp by its former management or staff

buy out in Finance 1
verb: When a company buys out another company, they purchase all of the stock of that company.

buy out in Finance 2
verb: If you buy out someone, you buy their share of a company or piece of property that you previously owned together.