Definition of "guard"

guard

/ɡɑːd/

noun
plural guards
1. A person who, or thing that, protects or watches over something.
  Quotations
  Sunning himself on the board steps, I saw for the first time Mr. Farquhar Fenelon Cooke. […] A silver snaffle on a heavy leather watch guard which connected the pockets of his corduroy waistcoat, together with a huge gold stirrup in his Ascot tie, sufficiently proclaimed his tastes.
  1897 December (indicated as 1898), Winston Churchill, chapter II, in The Celebrity: An Episode, New York, N.Y.: The Macmillan Company; London: Macmillan & Co., Ltd.
2. (Ireland) A garda; a police officer.
  Quotations
  The Garda Regulations 1924 required a candidate for appointment as a guard to be able to produce satisfactory references as to his character
  2016, Anastasia Dukova, A History of the Dublin Metropolitan Police and its Colonial Legacy, Springer, page 139
3. (military) A squad responsible for protecting something.
4. The part of a sword that protects the wielder's hand.
5. A part of a machine which blocks access to dangerous parts.
6. A watchchain.
7. (Australia) A panel of a car that encloses the wheel area, especially the front wheels.
  Quotations
  Another possible way is to go for a lower profile tyre (50 series). This effectively lowers the distance of the tyre wall away from the guard (not by much though and generally, the lower the profile, the wider the tyre so the tyre may stick out more as well).
  1996 December 24, Pendles, “Tyres rubbing on guards”, in aus.cars‎ (Usenet)
  The reason I'm asking - Whenever I put some weight in the back of the car (say - a passenger or two) the rear tyres can sometimes hit the guards.
  1999 November 23, Nathan, “Tyres rubbing on guards”, in aus.cars‎ (Usenet)
  I had just bought myself broken headlights, a f**ked up grill, a front guard bent into my front tyre, a leaky radiator and one *SLIGHTLY* bent chassis rail end. I turned the key on my stalled motor and she kicked over first go - if it weren't for the guard bent into the tyre, I could've driven home later if I wanted to.
  2001 June 12, Confusement, “Position N or D”, in alt.autos‎ (Usenet)
8. (uncountable) A state of caution; posture of defence.
9. Something worn to protect part of the body, e.g. the shins in cricket.
10. (basketball) A relatively short player, playing farther from the basket than a forward or centre.
11. (cricket) The position on the popping crease where a batsman makes a mark to align himself with the wicket; see take guard.
12. (American football) Either of two offensive positions between the centre and each of the offensive tackles, whose main responsibilities are to protect the quarterback, and open up "holes" through which offensive players can run.
13. (martial arts) A ground grappling position in which one combatant has their back to the ground while attempting to control the other combatant using their legs.
14. (sports) A player playing a position named guard.
15. (rail transport) An employee, normally travelling in the last vehicle of a train, responsible for the safety of the train.
  Quotations
  When an engineer wished to stop a swiftly moving train he had first to whistle to the guard requesting him to apply the hand-brake of the van, and then apply the hand-brake of the engine. Guards did not always hear.
  1938, Xavier Herbert, chapter IX, in Capricornia‎, New York: D. Appleton-Century, published 1943, page 141
16. (computing, programming) A Boolean expression that must evaluate to true for a branch of program execution to continue.
17. (aviation) The aircraft emergency frequency, a radio frequency reserved for emergency communications, typically 121.5MHz for civilian use.
verb
third-person singular simple present guards, present participle guarding, simple past and past participle guarded
1. (transitive) To protect from danger; to secure against surprise, attack, or injury; to keep in safety; to defend.
  Quotations
  For Heaven still guards the right.
  1595 December 9 (first known performance), William Shakespeare, “The life and death of King Richard the Second”, in Mr. William Shakespeares Comedies, Histories, & Tragedies: Published According to the True Originall Copies (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act III, scene ii]
  Henceforth, wherever thou may’st roam,⁠My blessing, like a line of light,⁠Is on the waters day and night,And like a beacon guards thee home.
  1850, [Alfred, Lord Tennyson], In Memoriam, London: Edward Moxon, […], canto XVII, page 28
2. (transitive) To keep watch over, in order to prevent escape or restrain from acts of violence, or the like.
3. (transitive, intransitive) To watch by way of caution or defense; to be cautious; to be in a state or position of defense or safety.
4. (transitive) To protect the edge of, especially with an ornamental border; hence, to face or ornament with lists, laces, etc.
  Quotations
  The body of your discourse is sometime guarded with fragments, and the guards are but slightly basted on neither.
  1598–1599 (first performance), William Shakespeare, “Much Adoe about Nothing”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, [Act I, scene i]
5. (transitive) To fasten by binding; to gird.