guard

Syllabification: (guard)

Pronunciation: /gärd/

Definition of guard

[with object]

watch over in order to protect or control:they were sent to guard villagers from attack by bandits the gates were guarded by uniformed soldiers
watch over (someone) to prevent them escaping:his task was to help guard Japanese soldiers
watch over (someone) to prevent them from escaping:police officers were guarding inmates who could not be accommodated in prison
[no object] (guard against) take precautions against:farmers must guard against sudden changes in the market
protect against damage or harm:the company fiercely guarded its independence
Basketball stay close to (an opponent) in order to prevent a good shot, pass, or drive.

1a person who keeps watch, especially a soldier or other person formally assigned to protect a person or to control access to a place:a security guard [as modifier]:he distracted the soldier on guard duty
[treated as singular or plural] a body of soldiers serving to protect a place or person:the hound belonged to a member of the castle’s guard
(Guards) the household troops of the British army.
a prison warder.
British an official who rides on and is in general charge of a train.
Football each of two offensive players positioned either side of the center.
Basketball each of two backcourt players chiefly responsible for running the team’s offense.

2a device worn or fitted to prevent injury or damage:a retractable blade guard
a chain attached to a watch or bracelet to prevent loss.

3a defensive posture adopted in a boxing, fencing, or martial arts contest or in a fight:this kick can curl around an otherwise effective guard
a state of caution, vigilance, or preparedness against adverse circumstances:he let his guard slip enough to make some unwise comments

Phrases

keep (or stand) guard: act as a guard.
lower (or let down) one's guard: relax one’s defensive posture, leaving oneself vulnerable to attack:if you lower your guard or take a step backward, I will throw in the towel; reduce one’s level of vigilance or caution:she was not ready to let down her guard and confide in him
off guard: unprepared for some surprise or difficulty:the government was caught off guard by the unexpected announcement
on guard: on duty to protect or defend something.; (also on one's guard) prepared for any contingency; vigilant:we must be on guard against such temptation
put up one's guard: adopt a defensive posture.
under guard: being guarded:he was held in an empty stable under guard

late Middle English (in the sense 'care, custody'): from Old French garde (noun), garder (verb), of West Germanic origin. Compare with ward

Remember that guard and the related word guardian begin with gua-.

Definition of guard in the British & World English dictionary