The Collaborative International Dictionary of English v.0.48:

Bunk \Bunk\ (b[u^][ng]k), n. [Cf. OSw. bunke heap, also boaring,
   flooring. Cf. Bunch.]
   1. A wooden case or box, which serves for a seat in the
      daytime and for a bed at night. [U.S.]
      [1913 Webster]

   2. One of a series of berths or bed places in tiers; as, to
      sleep in the top bunk.
      [1913 Webster]

   3. A piece of wood placed on a lumberman's sled to sustain
      the end of heavy timbers. [Local, U.S.]
      [1913 Webster]

   4. a bed. [informal]
      [PJC]

The Collaborative International Dictionary of English v.0.48:

Bunk \Bunk\, v. i. [imp. & p. p. Bunked; p. pr. & vb. n.
   Bunking.]
   To go to bed in a bunk; -- sometimes with in. [Colloq. U.S.]
   --Bartlett.
   [1913 Webster]

WordNet (r) 3.0 (2006):

bunk
    n 1: a long trough for feeding cattle [syn: bunk, feed bunk]
    2: a bed on a ship or train; usually in tiers [syn: berth,
       bunk, built in bed]
    3: a rough bed (as at a campsite)
    4: unacceptable behavior (especially ludicrously false
       statements) [syn: bunk, bunkum, buncombe, guff,
       rot, hogwash]
    5: a message that seems to convey no meaning [syn: nonsense,
       bunk, nonsensicality, meaninglessness, hokum]
    6: beds built one above the other [syn: bunk bed, bunk]
    v 1: avoid paying; "beat the subway fare" [syn: beat, bunk]
    2: provide with a bunk; "We bunked the children upstairs"
    3: flee; take to one's heels; cut and run; "If you see this man,
       run!"; "The burglars escaped before the police showed up"
       [syn: scat, run, scarper, turn tail, lam, run
       away, hightail it, bunk, head for the hills, take to
       the woods, escape, fly the coop, break away]

Moby Thesaurus II by Grady Ward, 1.0:

105 Moby Thesaurus words for "bunk":
   abide, abscond, applesauce, balderdash, balls, baloney, bed,
   bedstead, beguile, berth, bestow, betray, big talk, bilge, billet,
   blague, blah, blah-blah, board, bop, bosh, break, bull, bullshit,
   bunkum, claptrap, cohabit, couch, crap, decamp, delude, domicile,
   domiciliate, doss, doss down, double-cross, dwell, eyewash,
   fancy talk, fine talk, fish story, flam, flapdoodle, flee,
   flimflam, fly, four-flush, gammon, gas, guff, gup, gurney,
   hang out, harbor, highfalutin, highfaluting, hogwash, hoke, hokum,
   hooey, hot air, house, humbug, humbuggery, hut, inhabit, jazz,
   jiggery-pokery, kip, litter, live, lodge, malarkey, mislead,
   moonshine, nest, occupy, perch, piffle, poppycock, put up, quarter,
   remain, reside, room, roost, rot, scape, scat, sell out, shelter,
   shit, sofa, squat, stable, stay, stretcher, tall story, tall talk,
   tenant, the hay, the sack, tommyrot, tripe, wind