to keep safe from harm or danger; protect; watch over

to guard the ruler.

to keep under close watch in order to prevent escape, misconduct, etc.

to guard a prisoner.

to keep under control or restraint as a matter of caution or prudence

to guard one's temper.

to provide or equip with some safeguard or protective appliance, as to prevent loss, injury, etc.

Sports . to position oneself so as to obstruct or impede the movement or progress of (an opponent on offense)

The linebacker moved to his right to guard the end going out for a pass.

Chess . to protect (a piece or a square) by placing a piece in a supportive or defensive position relative to it.

to take precautions (usually fol. by against )

to guard against errors.

to give protection; keep watch; be watchful.

a person or group of persons that guards, protects, or keeps a protective or restraining watch.

a person who keeps watch over prisoners or others under restraint.

a body of people, esp. soldiers, charged with guarding a place from disturbance, theft, fire, etc.

a close watch, as over a prisoner or other person under restraint

to be kept under guard.

a device, appliance, or attachment that prevents injury, loss, etc.

something intended or serving to guard or protect; safeguard

insurance as a guard against disasters.

a posture of defense or readiness, as in fencing, boxing, or bayonet drill.

Football .

either of the linemen stationed between a tackle and the center.

the position played by this lineman.

Basketball . either of the players stationed in the backcourt.

Chess . a piece that supports or defends another.

Cards . a low card that is held with a high card of the same suit and that enables the holder to save the high card for a later trick.

British . a railroad conductor.

Guards, the name of certain bodies of troops in the British army. ?

off guard

unprepared; unwary

The blow from behind caught him off guard. Also, off one's guard.

on guard

vigilant; wary

on guard against dishonest merchants. Also, on one's guard.

stand guard over

to watch over; protect

The dog stood guard over his wounded master.

verb

disregard , forget , ignore , neglect , expose

noun

bouncer , chaperon , chaperone , chaser , convoyer , custodian , defender , escort , guardian , lookout , picket , sentinel , sentry , shepherd , shield , ward , warden , watch , watchperson , aegis , armament , armor , buffer , bulwark , pad , protection , rampart , safeguard , screen , security , protector , preservation

verb

attend , baby-sit , bulwark , chaperon , chaperone , conduct , convoy , cover , cover up , defend , escort , fend , keep , keep an eye on , keep in view , keep under surveillance , look after , lookout , mind , observe , oversee , patrol , police * , preserve , ride shotgun for , safeguard , save , screen , secure , see after , shelter , shepherd , shield , shotgun , stonewall * , superintend , supervise , tend , protect , ward , care , conserve , custodian , defense , fortify , garrison , herd , jailer , keeper , lineman , police , protector , restrain , security , sentinel , sentry , warden , warder , watch , watchdog , watchman