A giveaway is when an offensive player turns the ball over to the other team. A giveaway can be an interception, fumble, or other inadvertent miscue that results in the opposition gaining possession of the ball. The term applies because by committing a turnover, the offending team, "gives the ball away," to the opposition.
The term giveaway is generally applied to the whole team when discussing turnovers. Not every turnover is considered a giveaway, it depends on the circumstances. If a quarterback gets the ball into the receivers hands, and the receiver is hit so hard the ball comes loose and lands in the hands of the defender, it is not considered a giveaway (unless the receiver was not cradling the ball properly). It is a casual term and is not officially tracked by the NFL. Teams and sports analysts use more specific turnover figures to assess a team's potential to commit giveaways.