loop

From Middle English loupe (“noose, loop”), earlier lowp-knot (“loop-knot”), of North Germanic origin, from Old Norse hlaup (“a run”), used in the sense of a "running knot", from hlaupa (“to leap”), ultimately from Proto-Germanic *hlaupaną (“to leap, run”). Compare Swedish löp-knut (“loop-knot”), Danish løb-knude (“a running knot”), Danish løb (“a course”). More at leap. The verb is derived from the noun.

• IPA^(key): /luːp/
• Rhymes: -uːp
• Homophone: loupe

• Audio (Southern England)

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loop (plural loops)

1. A length of thread, line or rope that is doubled over to make an opening.
2. The opening so formed.
3. A shape produced by a curve that bends around and crosses itself.

   Arches, loops, and whorls are patterns found in fingerprints.

4. A ring road or beltway.
5. An endless strip of tape or film allowing continuous repetition.
6. A complete circuit for an electric current.
7. (programming) A programmed sequence of instructions that is repeated until or while a particular condition is satisfied.
8. (graph theory) An edge that begins and ends on the same vertex.
9. (topology) A path that starts and ends at the same point.
10. (transport) A bus or rail route, walking route, etc. that starts and ends at the same point.
11. (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, [...]

12. (algebra) A quasigroup with an identity element.
13. A loop-shaped intrauterine device.
14. An aerobatic maneuver in which an aircraft flies a circular path in a vertical plane.
15. A small, narrow opening; a loophole.
    • c. 1597 (date written), William Shakespeare, “The First Part of Henry the Fourth, […]”, in Mr. William Shakespeares Comedies, Histories, & Tragedies […] (First Folio), London: […] Isaac Iaggard, and Ed[ward] Blount, published 1623, →OCLC, [Act IV, scene i]:

      And stop all sight-holes, every loop from whence / The eye of Reason may pry in upon us.

16. Alternative form of loup (“mass of iron”)
17. (biochemistry) A flexible region in a protein's secondary structure.

• control structure

loop (third-person singular simple present loops, present participle looping, simple past and past participle looped)

1. (transitive) To form something into a loop.
2. (transitive) To fasten or encircle something with a loop.
3. (transitive) To fly an aircraft in a loop.
4. (transitive) To move something in a loop.
5. (transitive) To join electrical components to complete a circuit.
6. (transitive) To duplicate the route of a pipeline.
7. (transitive) To create an error in a computer program so that it runs in an endless loop and the computer freezes up.
8. (intransitive) To form a loop.
9. (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.

10. 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.

• Appendix:Parts of the knot

• loop on Wikipedia.Wikipedia

• OOPL, Polo, Pool, polo, pool

• IPA^(key): /lʊəp/

From Dutch lopen, from Middle Dutch lôpen, from Old Dutch lōpan, from Proto-West Germanic *hlaupan, from Proto-Germanic *hlaupaną (“to run”).

loop (present loop, present participle lopende, past participle geloop)

1. (intransitive) to walk

• loep (Western Cape)

From Dutch loop, from Middle Dutch lôop, from Old Dutch *lōp.

loop (plural lope, diminutive lopie)

1. walking, gait
2. (of events) course
3. (of guns) barrel
4. (informal) business end (of a rifle, etc.)
5. (music, usually in diminutive) run: a rapid passage in music, especially along a scale

From English loop.

loop

1. (Hong Kong Cantonese) to repeatedly consume or play songs or videos

   條片我loop咗幾百次 [Cantonese, trad.]
   条片我loop咗几百次 [Cantonese, simp.]

   tiu⁴ pin³ ngo⁵ lup¹ zo² gei² baak³ ci³ [Jyutping]

   I've repeatedly watched the video a few hundreds times

2. (Hong Kong Cantonese, by extension) to occur repeatedly

loop

1. (Hong Kong Cantonese) loop; cycle (Classifier: 個／个 c)

   無限loop／无限loop [Cantonese]  ―  mou⁴ haan⁶ lup¹ [Jyutping]  ―  infinite never-ending loop

• IPA^(key): /loːp/

• Audio

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• Hyphenation: loop
• Rhymes: -oːp

From Middle Dutch lôop, from Old Dutch *lōp.

loop m (plural lopen, diminutive loopje n)

1. course, duration
2. a river course
3. course of a projectile
4. barrel (of a firearm)

• lopen

• Afrikaans: loop
• → Indonesian: lop
• → Lokono: loporo
• → Papiamentu: lop

See the etymology of the corresponding lemma form.

loop

1. inflection of lopen:
   1. first-person singular present indicative
   2. imperative

• Pool, pool

Unadapted borrowing from English loop.

loop m (plural loops)

1. (computing) loop (repeating sequence of instructions)

   Synonyms: ciclo, laço

2. loop (aircraft manoeuvre)

   Synonym: looping

• in loop