Bought is the past tense of the verb “buy,” which means to get something by paying money for it. When you go to a store and exchange money for a candy bar, you bought that candy bar. When your parents purchased your house years ago, they bought it.

The word shows that the purchasing already happened. “I bought new shoes yesterday” tells us the transaction is complete, while “I will buy new shoes tomorrow” talks about the future.

Sometimes people use bought in phrases that have nothing to do with money. When someone says they're not “buying” your excuse, they mean they don't believe it. If a friend tells you an unbelievable story and you say “I'm not buying it,” you're saying you think they're making it up. Similarly, if someone “bought into” an idea, they accepted it or started believing in it, like when a team bought into their coach's strategy.

There's also an older phrase “dearly bought,” which means something cost a lot in effort or sacrifice as well as money. A hard-won victory might be called dearly bought if it required great struggle to achieve.