n a person who keeps watch over something or someone\nn the person who plays that position on a football team\nn a device designed to prevent injury or accidents\nn a posture of defence in boxing or fencing\nn the person who plays the position of guard on a basketball team\nn a military unit serving to protect some place or person\nn a precautionary measure warding off impending danger or damage or injury etc.\nn the duty of serving as a sentry\nn (American football) a position on the line of scrimmage\nn a position on a basketball team\nv to keep watch over\nv watch over or shield from danger or harm; protect\nv protect against a challenge or attack\nv take precautions in order to avoid some unwanted consequence