The Collaborative International Dictionary of English v.0.48:

Nick \Nick\ (n[i^]k), n. [AS. nicor a marine monster; akin to D.
   nikker a water spite, Icel. nykr, ONG. nihhus a crocodile, G.
   nix a water sprite; cf. Gr. ni`ptein to wash, Skr. nij. Cf.
   Nix.] (Northern Myth.)
   An evil spirit of the waters.
   [1913 Webster]

   Old Nick, the evil one; the devil. [Colloq.]
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Nick \Nick\, n. [Akin to Nock.]
   1. A notch cut into something; as:
      (a) A score for keeping an account; a reckoning. [Obs.]
      (b) (Print.) A notch cut crosswise in the shank of a type,
          to assist a compositor in placing it properly in the
          stick, and in distribution. --W. Savage.
          [1913 Webster]

   2. Hence: A broken or indented place in any edge or surface;
      as, nicks in a china plate; a nick in the table top.
      [1913 Webster]

   3. A particular point or place considered as marked by a
      nick; the exact point or critical moment.
      [1913 Webster]

            To cut it off in the very nick.       --Howell.
      [1913 Webster]

            This nick of time is the critical occasion for the
            gaining of a point.                   --L'Estrange.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Nick \Nick\, v. t.
   To nickname; to style. [Obs.]
   [1913 Webster]

         For Warbeck, as you nick him, came to me. --Ford.
   [1913 Webster] Nickar nut

The Collaborative International Dictionary of English v.0.48:

Nick \Nick\, v. t. [imp. & p. p. Nicked (n[i^]kt); p. pr. &
   vb. n. Nicking.]
   1. To make a nick or nicks in; to notch; to keep count of or
      upon by nicks; as, to nick a stick, tally, etc.
      [1913 Webster]

   2. To mar; to deface; to make ragged, as by cutting nicks or
      notches in; to create a nick[2] in, deliberately or
      accidentally; as, to nick the rim of a teacup.
      [1913 Webster +PJC]

            And thence proceed to nicking sashes. --Prior.
      [1913 Webster]

            The itch of his affection should not then
            Have nicked his captainship.          --Shak.
      [1913 Webster]

   3. To suit or fit into, as by a correspondence of nicks; to
      tally with.
      [1913 Webster]

            Words nicking and resembling one another are
            applicable to different significations. --Camden.
      [1913 Webster]

   4. To hit at, or in, the nick; to touch rightly; to strike at
      the precise point or time.
      [1913 Webster]

            The just season of doing things must be nicked, and
            all accidents improved.               --L'Estrange.
      [1913 Webster]

   5. To make a cross cut or cuts on the under side of (the tail
      of a horse, in order to make him carry it higher).
      [1913 Webster]

WordNet (r) 3.0 (2006):

nick
    n 1: an impression in a surface (as made by a blow) [syn:
         dent, ding, gouge, nick]
    2: (British slang) a prison; "he's in the nick"
    3: a small cut [syn: notch, nick, snick]
    v 1: cut slightly, with a razor; "The barber's knife nicked his
         cheek" [syn: nick, snick]
    2: cut a nick into [syn: nick, chip]
    3: divide or reset the tail muscles of; "nick horses"
    4: mate successfully; of livestock

Moby Thesaurus II by Grady Ward, 1.0:

195 Moby Thesaurus words for "nick":
   Vandyke, appropriate, arrest, ascender, back, bastard type, beard,
   beat it, belly, bevel, birthmark, black letter, blaze,
   blaze a trail, blemish, blotch, body, brand, cabbage, cap, capital,
   case, cast, caste mark, chalk, chalk up, check, check off,
   checkmark, chip, chop, cicatrix, cicatrize, cleft, clout, collar,
   counter, crap, craps, crena, crenellate, crenulate, crimp, cut,
   dapple, dash, defect, define, delimit, demarcate, dent, depart,
   depression, descender, discolor, discoloration, dot, earmark, em,
   en, engrave, engraving, face, fat-faced type, feet, flaw, fleck,
   flick, font, freckle, gash, gouge, graving, groove, hack, hatch,
   hook, impress, imprint, incise, incision, indent, indentation,
   indenture, italic, jag, jog, joggle, jot, kerf, knurl, lentigo,
   letter, ligature, line, logotype, lower case, machicolate, macula,
   majuscule, make a mark, make off with, make tracks, mark, mark off,
   mark out, marking, mill, minuscule, mole, mottle, nab, nail,
   natural, nevus, nip, nock, notch, patch, pencil, pepper, pi, pica,
   picot, pinch, pink, point, police station, polka dot, prick, print,
   punch, punctuate, puncture, purloin, riddle, roll, roman,
   sans serif, scallop, scar, scarification, scarify, score, scotch,
   scratch, scratching, script, seal, seam, serrate, shank, shot,
   shoulder, slash, small cap, small capital, speck, speckle, splash,
   splotch, spot, stain, stamp, steal, stem, stigma, stigmatize,
   strawberry mark, streak, striate, stripe, take, take in, take off,
   tattoo, tattoo mark, throw, tick, tick off, tittle, tooth, trace,
   type, type body, type class, type lice, typecase, typeface,
   typefounders, typefoundry, underline, underscore, upper case,
   watermark



The Jargon File (version 4.4.7, 29 Dec 2003):

nick
 n.

    [IRC; very common] Short for nickname. On IRC, every user must pick a
    nick, which is sometimes the same as the user's real name or login name,
    but is often more fanciful. Compare handle, screen name.


The Free On-line Dictionary of Computing (30 December 2018):

nick

   [IRC] nickname.  On IRC, every user must pick a nick, which
   is sometimes the user's real name or login name, but is often
   more fanciful.  Compare handle.

   [Jargon File]