The noun guard has 10 senses (first 4 from tagged texts)
1. (15) guard -- (a person who keeps watch over something or someone)
2. (2) guard -- (the person who plays that position on a football team; "the left guard was injured on the play")
3. (2) guard, safety, safety device -- (a device designed to prevent injury)
4. (1) guard -- (a posture of defence in boxing or fencing; "keep your guard up")
5. guard -- (the person who plays the position of guard on a basketball team)
6. guard, bodyguard -- (a group of men who escort and protect some important person)
7. precaution, safeguard, guard -- (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. guard duty, guard, sentry duty, sentry go -- (the duty of serving as a sentry; "he was on guard that night")
9. guard -- (a position on the line of scrimmage; "guards must be good blockers")
10. guard -- (a position on a basketball team)
Overview of verb guard
The verb guard has 4 senses (first 3 from tagged texts)
1. (6) guard -- (to keep watch over; "there would be men guarding the horses")
2. (6) guard, ward -- (watch over or shield from danger or harm; protect; "guard my possessions while I'm away")
3. (2) defend, guard, hold -- (protect against a challenge or attack; "Hold that position behind the trees!"; "Hold the bridge against the enemy's attacks")
4. guard -- (take precautions in order to avoid some unwanted consequence; "guard against becoming too friendly with the staff"; "guard against infection")