The Collaborative International Dictionary of English v.0.48:

Loop \Loop\, n. [Cf. Ir. & Gael. lub loop, noose, fold, thong,
   bend, lub to bend, incline.]
   1. 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.
      [1913 Webster]

            That the probation bear no hinge, nor loop
            To hang a doubt on.                   --Shak.
      [1913 Webster]

   2. A small, narrow opening; a loophole.
      [1913 Webster]

            And stop all sight-holes, every loop from whence
            The eye of Reason may pry in upon us. --Shak.
      [1913 Webster]

   3. A curve of any kind in the form of a loop.
      [1913 Webster]

   4. (Telegraphy) A wire forming part of a main circuit and
      returning to the point from which it starts.
      [1913 Webster]

   5. (Acoustics) The portion of a vibrating string, air column,
      etc., between two nodes; -- called also ventral segment.
      [1913 Webster]

   Loop knot, a single knot tied in a doubled cord, etc. so as
      to leave a loop beyond the knot. See Illust. of Knot.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Loop \Loop\ (l[=oo]p), n. [G. luppe an iron lump. Cf.
   Looping.] (Iron Works)
   A mass of iron in a pasty condition gathered into a ball for
   the tilt hammer or rolls. [Written also loup.]
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Loop \Loop\ (l[=oo]p), v. t. [imp. & p. p. Looped (l[=oo]pt);
   p. pr. & vb. n. Looping.]
   To make a loop of or in; to fasten with a loop or loops; --
   often with up; as, to loop a string; to loop up a curtain.
   [1913 Webster]

WordNet (r) 3.0 (2006):

loop
    n 1: fastener consisting of a metal ring for lining a small hole
         to permit the attachment of cords or lines [syn: cringle,
         eyelet, loop, grommet, grummet]
    2: anything with a round or oval shape (formed by a curve that
       is closed and does not intersect itself)
    3: (computer science) a single execution of a set of
       instructions that are to be repeated; "the solution took
       hundreds of iterations" [syn: iteration, loop]
    4: an inner circle of advisors (especially under President
       Reagan); "he's no longer in the loop"
    5: the basic pattern of the human fingerprint
    6: a computer program that performs a series of instructions
       repeatedly until some specified condition is satisfied
    7: the topology of a network whose components are serially
       connected in such a way that the last component is connected
       to the first component [syn: loop topology, loop]
    8: an intrauterine device in the shape of a loop
    9: a complete electrical circuit around which current flows or a
       signal circulates [syn: closed circuit, loop] [ant: open
       circuit]
    10: a flight maneuver; aircraft flies a complete circle in the
        vertical plane [syn: loop, loop-the-loop]
    v 1: move in loops; "The bicycle looped around the tree"
    2: make a loop in; "loop a rope" [syn: loop, intertwine]
    3: fly loops, perform a loop; "the stunt pilot looped his plane"
    4: wind around something in coils or loops [syn: coil, loop,
       curl] [ant: uncoil]
    5: fasten or join with a loop; "He looped the watch through his
       belt"

The Free On-line Dictionary of Computing (19 January 2023):

loop
loop through

    A sequence of instructions in a program that
   the processor repeats.  The loop will usually terminate when
   some condition is met or it may run indefinitely - an
   infinite loop.

   Structured languages like C and its descendents provide
   loop statements and keywords for some or all of for
   loop, while loop and repeat loop.  See also
   loop-and-a-half.

   In other languages these constructs may be synthesised with a
   jump (assembly language) or a GOTO (early Fortran or
   BASIC).

   To "loop through" a list means to process each element in turn.

   (2019-09-03)