loop

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A length of line, thread, ribbon, or other thin material that is curved or doubled over making an opening.
2. n. The opening formed by such a doubled line.
3. n. Something having a shape, order, or path of motion that is circular or curved over on itself.
4. n. Electricity A closed circuit.
5. n. Computer Science A sequence of instructions that repeats either a specified number of times or until a particular condition is met.
6. n. A type of loop-shaped intrauterine device.
7. n. A flight maneuver in which an aircraft flies a circular path in a vertical plane with the lateral axis of the aircraft remaining horizontal.
8. n. A segment of film or magnetic tape whose ends are joined, making a strip that can be continuously replayed.
9. n. Sports See league¹.
10. v. To form into a loop.
11. v. To fasten, join, or encircle with loops or a loop.
12. v. To fly (an aircraft) in a loop.
13. v. To move in a loop or an arc.
14. v. Electricity To join (conductors) so as to complete a circuit.
15. v. To add or substitute (words) in a film by altering the sound track.
16. v. To form a loop.
17. v. To move in a loop: "The couple looped constantly around the international social circuit” ( Walter Isaacson).
18. v. To make a loop in an aircraft.
19. idiom. in the loop Part of a group that is kept up-to-date with information about something: knew about the merger because she's in the loop.
20. idiom. knock Slang To surprise tremendously; astonish.
21. idiom. out of the loop Not part of a group that is kept up-to-date with information about something.
22. n. Archaic A loophole through which small arms may be fired.

Century Dictionary and Cyclopedia

1. n. A folding or doubling of a string, lace, cord, chain, etc., or a short piece doubled and secured to something at each end. By a loop is most commonly understood a part or piece of some material bent and secured in such a way as to form an eye or opening through which something can be passed; but it may be merely an unfastened returning curve in the material, the shape giving the name.
2. n. Something resembling a loop, as the bend of a river; a link; a crook.
3. n. Specifically.
4. n. In crochet, knitting, and similar kinds of fancy work, same as stitch.
5. n. A hinge of a door.
6. n. In railroad and telegraph systems, a branch line leaving the main line at any point and joining it again at some other point; a looping line, as a branch wire carried over to a side station and back.
7. n. In the theory of Riemann's surfaces, a line running from any point to a branchpoint, then around that branch-point in an infinitesimal circle, and back to the original point by the same path.
8. n. A part of a curve limited by a crunode.
9. n. The ear of a vessel, as a stoneware jar, when approximately of the form of half-ring projecting from the side or lip.
10. n. In gunnery, a small fron ring in the barrel of a gun.
11. n. The small ring at the tip of a fishing-rod through which the line passes.
12. n. In anatomy, a looped vessel or fiber; especially, a nerve-loop.
13. n. In brachiopods, the folding of the brachial appendages.
14. n. In acoustics, the part of a vibrating musical string (see sonometer), or, as in an organ-pipe, of a column of air, where the amplitude of vibration is at its maximum. See node.
15. n. In mech., a slotted bar or ring at the side of any piece of machinery, designed to limit or control the movement of another part.
16. n. A knot or bur, often of great size, occurring on walnut, maple, oak, and some other trees. The wood of these knots is curled and waved in grain, and is used to make veneers for ornamental furniture.
17. n. A small magnifying-glass.
18. To form into a loop or loops: as, to loop a cord.
19. To fasten or secure with a loop or loops: as, to loop up a curtain.
20. To furnish with a loop or loops: as, to loop a cloak.
21. To form a loop.
22. To move, as the larvæ of certain moths, by forming loops.
23. n. A narrow window; any small, narrow aperture; specifically, in medieval fortification, a small aperture for observing the enemy, for the discharge of arrows or ordnance, or to admit light; a loophole.
24. n. A gap in the paling of a park, made for the convenience of the deer.
25. n. A removable fence-panel made of parallel wooden bars, generally united by transverse braces or crosspieces, used as a substitute for an ordinary fence-gate. Instead of being hinged, it is generally supported by notched brackets, or other supports adapted to receive the ends of the bars.
26. n. See loupe.
27. n. In physical, that region, in a standing wave system, for which the amplitude of vibration is a maximum: opposed to node, which is the region of zero amplitude.

Wiktionary

1. n. A length of thread, line or rope that is doubled over to make an opening; the opening so formed
2. n. A shape produced by a curve that bends around and crosses itself.
3. n. An endless strip of tape or film allowing continuous repetition.
4. n. A complete circuit for an electric current.
5. n. computing A programmed sequence of instructions that is repeated until or while a particular condition is satisfied.
6. n. graph theory An edge that begins and ends on the same vertex.
7. n. A loop-shaped intrauterine device
8. n. a maneuver in which an aircraft flies a circular path in a vertical plane
9. v. transitive To form something into a loop
10. v. transitive To fasten or encircle something with a loop
11. v. transitive To fly an aircraft in a loop
12. v. transitive To move something in a loop
13. v. transitive To join electrical components to complete a circuit
14. v. intransitive To form a loop
15. v. intransitive To move in a loop

GNU Webster's 1913

1. n. (Iron Works) A mass of iron in a pasty condition gathered into a ball for the tilt hammer or rolls.
2. n. A fold or doubling of a thread, cord, rope, etc., through which another thread, cord, etc., can be passed, or which a hook can be hooked into; an eye, as of metal; a staple; a noose; a bight.
3. n. A small, narrow opening; a loophole.
4. n. A curve of any kind in the form of loop.
5. n. (Telegraphy) A wire forming part of a main circuit and returning to the point from which it starts.
6. n. (Acoustics) The portion of a vibrating string, air column, etc., between two nodes; -- called also ventral segment.
7. v. To make a loop of or in; to fasten with a loop or loops; -- often with up

WordNet 3.0

1. v. fasten or join with a loop
2. n. an intrauterine device in the shape of a loop
3. n. anything with a round or oval shape (formed by a curve that is closed and does not intersect itself)
4. n. a flight maneuver; aircraft flies a complete circle in the vertical plane
5. n. (computer science) a single execution of a set of instructions that are to be repeated
6. n. the basic pattern of the human fingerprint
7. v. move in loops
8. v. fly loops, perform a loop
9. n. a complete electrical circuit around which current flows or a signal circulates
10. v. wind around something in coils or loops
11. n. fastener consisting of a metal ring for lining a small hole to permit the attachment of cords or lines
12. v. make a loop in
13. n. the topology of a network whose components are serially connected in such a way that the last component is connected to the first component
14. n. a computer program that performs a series of instructions repeatedly until some specified condition is satisfied
15. n. an inner circle of advisors (especially under President Reagan)