Definition of Guard

Noun: guard gaa(r)d

A person who keeps watch over something or someone
The person who plays that position on a football team
"the left guard was injured on the play"
A device designed to prevent injury or accidents
- safety, safety device
A posture of defence in boxing or fencing
"keep your guard up"
The person who plays the position of guard on a basketball team
A military unit serving to protect some place or person
A precautionary measure warding off impending danger, damage or injury etc.
"we let our guard down";
- precaution, safeguard
The duty of serving as a sentry
"he was on guard that night";
- guard duty, sentry duty, sentry go
(American football) a position on the line of scrimmage
"guards must be good blockers"
A position on a basketball team

Verb: guard gaa(r)d

To keep watch over
"there would be men guarding the horses"
Watch over or shield from danger or harm; protect
"guard my possessions while I'm away";
- ward
Protect against a challenge or attack
"guard that position behind the trees!";
- defend, hold
Take precautions in order to avoid some unwanted consequence
"guard against becoming too friendly with the staff"; "guard against infection"