To give away means to hand something over to someone else for free, without expecting payment or anything in return. When you give away your old toys to a younger cousin, you're letting them have those toys permanently. A store might give away free samples of cookies to customers, or a radio station might give away concert tickets to lucky callers.

The phrase can also mean revealing a secret, often accidentally. If you're planning a surprise party and accidentally mention it to the birthday person, you've given away the secret. A poker player might give away their hand by smiling when they get good cards. In mysteries, a small clue might give away the ending before you reach the last chapter.

People sometimes use giveaway as a single word to describe something free that's being offered, like “Enter our giveaway to win a new bike.” A giveaway can also be a telltale sign that reveals the truth about something: “His nervous laugh was a dead giveaway that he knew more than he was saying.”