to buy a part of a company or building from someone else so that you own all of it

Allied Chemicals have been trying to buy out their competitor's share in the target company. 联合化工公司一直在试图买下其竞争对手在他们想要收购的公司的股份。

If you buy yourself out of the armed forces, you pay an amount of money so that you can leave earlier than you had previously agreed to.