To advertise means to publicly announce or promote something you want people to know about, buy, or support. Companies advertise their products through commercials, billboards, and online ads, hoping to convince customers that their sneakers, breakfast cereal, or video games are worth buying. When a store advertises a sale, they're spreading the word about lower prices to attract shoppers.

When you advertise something, you're essentially saying “pay attention to this!” A school might advertise tryouts for the basketball team by posting signs in hallways. A kid might advertise their lawn-mowing service by putting flyers in neighbors' mailboxes.

You can also advertise things unintentionally. If you walk around grinning all day, you're advertising your good mood. If someone keeps checking their watch during a conversation, they're inadvertently advertising their impatience or boredom.

Modern advertising has become incredibly sophisticated, using psychology, art, humor, and celebrity endorsements to capture attention and shape what people want.