safety

The condition of being safe; freedom from danger, risk, or injury.

A device designed to prevent accidents, as a lock on a firearm preventing accidental firing.

A play in which a member of the offensive team downs the ball or is tackled or forced out of bounds behind his own goal line, resulting in two points for the defensive team.

Either of two defensive backs normally positioned behind the linebackers in the middle of the backfield.

Defensive strategy at billiards. In America, since 1879, deliberate resort to misses has been restricted by limiting such misses to three in succession, and contingently to two.