Noun
1. a person who keeps watch over something or someone
2. the person who plays that position on a football team;
"the left guard was injured on the play"3. a device designed to prevent injury
4. a posture of defence in boxing or fencing;
"keep your guard up"5. the person who plays the position of guard on a basketball team
6. a group of men who escort and protect some important person
7. a precautionary measure warding off impending danger or damage or injury etc.;
"he put an ice pack on the injury as a precaution""an insurance policy is a good safeguard""we let our guard down"8. the duty of serving as a sentry;
"he was on guard that night"9. a position on the line of scrimmage;
"guards must be good blockers"10. a position on a basketball team