From Middle English loupe (“noose, loop”), earlier lowp-knot (“loop-knot”), of North Germanic origin, from Old Norse hlaup (“a run", literally, "a leap”), used in the sense of a "running knot", from hlaupa (“to leap”), ultimately from Proto-Germanic *hlaupaną. Compare Swedish löp-knut (“loop-knot”), Danish løb-knude (“a running knot”), Danish løb (“a course”). More at leap.
loop (plural loops)
- A length of thread, line or rope that is doubled over to make an opening.
- The opening so formed.
- A shape produced by a curve that bends around and crosses itself.
- Arches, loops, and whorls are patterns found in fingerprints.
- A ring road or beltway.
- An endless strip of tape or film allowing continuous repetition.
- A complete circuit for an electric current.
- (programming) A programmed sequence of instructions that is repeated until or while a particular condition is satisfied.
- (graph theory) An edge that begins and ends on the same vertex.
- (topology) A path that starts and ends at the same point.
- (transport) A bus or rail route, walking route, etc. that starts and ends at the same point.
- (rail transport) A place at a terminus where trains or trams can turn round and go back the other way without having to reverse; a balloon loop, turning loop, or reversing loop.
- 2012, Andrew Martin, Underground Overground: A passenger's history of the Tube, Profile Books, →ISBN, page 119:
- In 1908 the line was extended to a station called Wood Lane, which was built on a terminal track loop so that trains could turn round and go back the other way, [...]
- (algebra) A quasigroup with an identity element.
- A loop-shaped intrauterine device.
- An aerobatic maneuver in which an aircraft flies a circular path in a vertical plane.
- A small, narrow opening; a loophole.
- c. 1597, William Shakespeare, “The First Part of Henry the Fourth, […]”, 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, OCLC 606515358, [Act IV, scene i]:
- And stop all sight-holes, every loop from whence / The eye of Reason may pry in upon us.
- Alternative form of (mass of iron).
- (biochemistry) A flexible region in a protein's secondary structure.
- The translations below need to be checked and inserted above into the appropriate translation tables, removing any numbers. Numbers do not necessarily match those in definitions. See instructions at Wiktionary:Entry layout § Translations.
From the noun.
- (transitive) To form something into a loop.
- (transitive) To fasten or encircle something with a loop.
- (transitive) To fly an aircraft in a loop.
- (transitive) To move something in a loop.
- (transitive) To join electrical components to complete a circuit.
- (transitive) To duplicate the route of a pipeline.
- (transitive) To create an error in a computer program so that it runs in an endless loop and the computer freezes up.
- (intransitive) To form a loop.
- (intransitive) To move in a loop.
- The program loops until the user presses a key.
- 2011 February 4, Gareth Roberts, “Wales 19-26 England”, in BBC:
- The outstanding Tom Palmer won a line-out and then charged into the heart of the Welsh defence, scrum-half Ben Youngs moved the ball swiftly right and Cueto's looping pass saw Ashton benefit from a huge overlap to again run in untouched.
- To place in a loop.
- 2021 January 13, Richard Clinnick, “Longer freight trains boost efficiency and reduce carbon”, in Rail, page 10:
- It found that trains often looped on their journey emit 14% to 20% more NOx and particulates than non-stop services.
- walking, gait
- (of events) course
- (of guns) barrel
- (informal) business end (of a rifle, etc.)
- (music, usually in diminutive) run: a rapid passage in music, especially along a scale
- to walk
See the etymology of the main entry.
loop m (plural loops)