The Collaborative International Dictionary of English v.0.48:

Bob \Bob\ (b[o^]b), n. [An onomatopoetic word, expressing quick,
   jerky motion; OE. bob bunch, bobben to strike, mock, deceive.
   Cf. Prov. Eng. bob, n., a ball, an engine beam, bunch, blast,
   trick, taunt, scoff; as, a v., to dance, to courtesy, to
   disappoint, OF. bober to mock.]
   1. Anything that hangs so as to play loosely, or with a short
      abrupt motion, as at the end of a string; a pendant; as,
      the bob at the end of a kite's tail.
      [1913 Webster]

            In jewels dressed and at each ear a bob. --Dryden.
      [1913 Webster]

   2. A knot of worms, or of rags, on a string, used in angling,
      as for eels; formerly, a worm suitable for bait.
      [1913 Webster]

            Or yellow bobs, turned up before the plow,
            Are chiefest baits, with cork and lead enow.
                                                  --Lauson.
      [1913 Webster]

   3. A small piece of cork or light wood attached to a fishing
      line to show when a fish is biting; a float.
      [1913 Webster]

   4. The ball or heavy part of a pendulum; also, the ball or
      weight at the end of a plumb line.
      [1913 Webster]

   5. A small wheel, made of leather, with rounded edges, used
      in polishing spoons, etc.
      [1913 Webster]

   6. A short, jerking motion; act of bobbing; as, a bob of the
      head.
      [1913 Webster]

   7. (Steam Engine) A working beam.
      [1913 Webster]

   8. A knot or short curl of hair; also, a bob wig.
      [1913 Webster]

            A plain brown bob he wore.            --Shenstone.
      [1913 Webster]

   9. A peculiar mode of ringing changes on bells.
      [1913 Webster]

   10. The refrain of a song.
       [1913 Webster]

             To bed, to bed, will be the bob of the song.
                                                  --L'Estrange.
       [1913 Webster]

   11. A blow; a shake or jog; a rap, as with the fist.
       [1913 Webster]

   12. A jeer or flout; a sharp jest or taunt; a trick.
       [1913 Webster]

             He that a fool doth very wisely hit,
             Doth very foolishly, although he smart,
             Not to seem senseless of the bob.    --Shak.
       [1913 Webster]

   13. A shilling. [Slang, Eng.] --Dickens.
       [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Bob \Bob\, v. i.
   1. To have a short, jerking motion; to play to and fro, or up
      and down; to play loosely against anything. "Bobbing and
      courtesying." --Thackeray.
      [1913 Webster]

   2. To angle with a bob. See Bob, n., 2 & 3.
      [1913 Webster]

            He ne'er had learned the art to bob
            For anything but eels.                --Saxe.
      [1913 Webster]

   To bob at an apple, cherry, etc. to attempt to bite or
      seize with the mouth an apple, cherry, or other round
      fruit, while it is swinging from a string or floating in a
      tug of water.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Bob \Bob\, v. t. [imp. & p. p. Bobbed; p. pr. & vb. n.
   Bobbing.] [OE. bobben. See Bob, n.]
   1. To cause to move in a short, jerking manner; to move (a
      thing) with a bob. "He bobbed his head." --W. Irving.
      [1913 Webster]

   2. To strike with a quick, light blow; to tap.
      [1913 Webster]

            If any man happened by long sitting to sleep . . .
            he was suddenly bobbed on the face by the servants.
                                                  --Elyot.
      [1913 Webster]

   3. To cheat; to gain by fraud or cheating; to filch.
      [1913 Webster]

            Gold and jewels that I bobbed from him. --Shak.
      [1913 Webster]

   4. To mock or delude; to cheat.
      [1913 Webster]

            To play her pranks, and bob the fool,
            The shrewish wife began.              --Turbervile.
      [1913 Webster]

   5. To cut short; as, to bob the hair, or a horse's tail.
      [1913 Webster]

WordNet (r) 3.0 (2006):

bob
    n 1: a former monetary unit in Great Britain [syn: British
         shilling, shilling, bob]
    2: a hair style for women and children; a short haircut all
       around
    3: a long racing sled (for 2 or more people) with a steering
       mechanism [syn: bobsled, bobsleigh, bob]
    4: a hanging weight, especially a metal ball on a string
    5: a small float usually made of cork; attached to a fishing
       line [syn: bob, bobber, cork, bobfloat]
    6: a short or shortened tail of certain animals [syn: bobtail,
       bob, dock]
    7: a short abrupt inclination (as of the head); "he gave me a
       short bob of acknowledgement"
    v 1: move up and down repeatedly; "her rucksack bobbed gently on
         her back"
    2: ride a bobsled; "The boys bobbed down the hill screaming with
       pleasure" [syn: bobsled, bob]
    3: remove or shorten the tail of an animal [syn: dock, tail,
       bob]
    4: make a curtsy; usually done only by girls and women; as a
       sign of respect; "She curtsied when she shook the Queen's
       hand" [syn: curtsy, bob]
    5: cut hair in the style of a bob; "Bernice bobs her hair these
       days!"

Moby Thesaurus II by Grady Ward, 1.0:

327 Moby Thesaurus words for "bob":
   Carling float, T square, abbreviate, abridge, abscind, abstract,
   accost, address, amputate, angle, annihilate, bait the hook, balsa,
   balsa raft, ban, bar, barber, bawbee, bend, bend the knee,
   bend the neck, bending the knee, bis, bob a curtsy, bob down,
   bobble, boil down, boom, bounce, bow, bow and scrape, bow down,
   bow the head, bowing and scraping, bump, buoy, burden, caper,
   capriole, capsulize, caracole, careen, cavort, chant, chatter,
   chorus, clam, clip, coggle, coif, coiffure, compress, condense,
   conk, contract, cork, crop, crouch, crown, cull, curtail, curtsy,
   curvet, cut, cut a dido, cut away, cut back, cut capers, cut down,
   cut off, cut off short, cut out, cut short, dangle, dap, dib,
   dibble, didder, dipping the colors, dither, ditto, dock, dollar,
   drive, duck, elide, eliminate, embrace, enucleate, epitomize,
   eradicate, except, excise, exclude, extinguish, extirpate,
   fall down before, falter, farthing, fish, fiver, flick, flip,
   flirt, float, florin, flounce, fluctuate, flutter, fly-fish,
   foreshorten, fourpence, fourpenny, frisk, gambado, gambol,
   genuflect, genuflection, gig, go fishing, greeting, grig, grimace,
   groat, guddle, guinea, hail, half crown, half dollar, halfpenny,
   hand-clasp, handshake, have an ague, hello, hitch, homage,
   how-do-you-do, hug, hustle, inclination, isolate, jack, jacklight,
   jactitate, jar, jerk, jig, jigget, jiggle, jog, joggle, jolt,
   jostle, jounce, jump, jump about, kiss, kneel, kneeling, knock,
   knock off, kowtow, lead, librate, life buoy, life preserver,
   life raft, lop, lurch, mag, make a leg, make a reverence,
   make obeisance, making a leg, meg, mite, monkey, mow, mutilate,
   net, new pence, nip, nod, np, nutate, obeisance, obsequiousness,
   oscillate, p, pare, peel, pence, pendulate, penny, pick out, pitch,
   pluck, plumb, plumb bob, plumb line, plumb rule, plummet, poll,
   pollard, pompadour, pontoon, pony, pound, prance, presenting arms,
   process, prostration, prune, quake, quaver, quid, quiver, raft,
   ramp, rap, reap, recap, recapitulate, reduce, reel, refrain,
   repeat, repetend, resonate, retrench, reverence, rictus,
   ritornello, rock, roll, romp, root out, rule out, salaam,
   salutation, salute, sandbag, scrape, seine, servility, set apart,
   set aside, set square, shake, shave, shear, shilling, shingle,
   shiver, shock, shorten, shrimp, shudder, sinker, sixpence, skip,
   smile, smile of recognition, snatch, snub, spin, square, squat,
   stamp out, standing at attention, start, still-fish, stoop,
   strike off, strip, strip off, stunt, submission, submissiveness,
   sudden pull, sum up, summarize, supination, surfboard, swag, sway,
   swing, synopsize, take in, take off, take out, telescope, tenner,
   threepence, threepenny bit, thrippence, tic, torch, toss, trawl,
   tremble, tremor, trim, trip, troll, truncate, try square, tunk,
   tuppence, tweak, twitch, twitter, twopence, undersong, vacillate,
   vibrate, wag, waggle, wave, waver, weight, whale, wipe out, wobble,
   wrench, yank, yerk



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

bob
 n.

    At Demon Internet, all tech support personnel are called ?Bob?. (Female
    support personnel have an option on ?Bobette?). This has nothing to do with
    Bob the divine drilling-equipment salesman of the Church of the SubGenius
    . Nor is it acronymized from ?Brother Of BOFH?, though all parties agree
    it could have been. Rather, it was triggered by an unusually large draft of
    new tech-support people in 1995. It was observed that there would be much
    duplication of names. To ease the confusion, it was decided that all
    support techs would henceforth be known as ?Bob?, and identity badges were
    created labelled ?Bob 1? and ?Bob 2?. (?No, we never got any further?
    reports a witness).

    The reason for ?Bob? rather than anything else is due to a luser calling
    and asking to speak to ?Bob?, despite the fact that no ?Bob? was currently
    working for Tech Support. Since we all know ?the customer is always right?,
    it was decided that there had to be at least one ?Bob? on duty at all
    times, just in case.

    This sillyness snowballed inexorably. Shift leaders and managers began to
    refer to their groups of ?bobs?. Whole ranks of support machines were set
    up (and still exist in the DNS as of 1999) as bob1 through bobN. Then came
    alt.tech-support.recovery, and it was filled with Demon support personnel.
    They all referred to themselves, and to others, as ?bob?, and after a while
    it caught on. There is now a Bob Code describing the Bob nature.


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

Bob

   David Betz.  A tiny object-oriented language.

   (ftp://ftp.mv.com/pub/ddj/packages/bob15.arc).

   [Dr Dobbs J, Sep 1991, p.26].