The Collaborative International Dictionary of English v.0.48:

Rift \Rift\, obs.
   p. p. of Rive. --Spenser.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Rift \Rift\, n. [Written also reft.] [Dan. rift, fr. rieve to
   rend. See Rive.]
   1. An opening made by riving or splitting; a cleft; a
      fissure. --Spenser.
      [1913 Webster]

   2. A shallow place in a stream; a ford.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Rift \Rift\, v. t. [imp. & p. p. Rifted; p. pr. & vb. n.
   Rifting.]
   To cleave; to rive; to split; as, to rift an oak or a rock;
   to rift the clouds. --Longfellow.
   [1913 Webster]

         To dwell these rifted rocks between.     --Wordsworth.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Rift \Rift\, v. i.
   1. To burst open; to split. --Shak.
      [1913 Webster]

            Timber . . . not apt to rif with ordnance. --Bacon.
      [1913 Webster]

   2. To belch. [Prov. Eng. & Scot.]
      [1913 Webster]

WordNet (r) 3.0 (2006):

rift
    n 1: a gap between cloud masses; "the sun shone through a rift
         in the clouds"
    2: a narrow fissure in rock
    3: a personal or social separation (as between opposing
       factions); "they hoped to avoid a break in relations" [syn:
       rupture, breach, break, severance, rift, falling
       out]

Moby Thesaurus II by Grady Ward, 1.0:

209 Moby Thesaurus words for "rift":
   abysm, abyss, alienation, arroyo, birthmark, blackhead, bleb,
   blemish, blister, box canyon, breach, breach of friendship, break,
   breakage, broach, bug, bulla, burst, canyon, catch, cavity, chap,
   chasm, check, chimney, chink, chinky, chip, cicatrix, cleavage,
   cleave, cleft, cleuch, clough, cloven, col, comedo, conflict,
   coulee, couloir, crack, cracked, cranny, crater, craze, crevasse,
   crevice, cut, cut open, cwm, defacement, defect, defection,
   deficiency, defile, deformation, deformity, dehiscent, dell,
   difference, dike, disaffection, disagreement, disfavor,
   disfiguration, disfigurement, dispart, disruption, distance,
   distortion, disunion, disunity, ditch, divaricate, divergence,
   divide, dividedness, division, donga, draw, drawback, estrangement,
   excavation, failing, failure, falling-out, fault, faute, fissure,
   fissured, fissury, flaw, flume, fly open, foible, fracture,
   frailty, freckle, furrow, gap, gape, gaping, gappy, gash, gorge,
   groove, gulch, gulf, gully, hemangioma, hiatus, hickey, hole,
   imperfection, inadequacy, incise, incision, infirmity,
   interruption, interval, joint, keloid, kink, kloof, lay open, leak,
   lentigo, little problem, milium, moat, mole, needle scar, nevus,
   notch, nullah, ope, open, open rupture, open up, opening, part,
   pass, passage, pimple, pit, pock, pockmark, port-wine mark,
   port-wine stain, problem, pustule, ravine, recall of ambassadors,
   rent, rime, rimose, rimulose, rip, rive, rupture, scab, scale,
   scar, schism, scissure, scratch, seam, sebaceous cyst, separate,
   separation, shortcoming, slash, slice, slit, slot, snag,
   something missing, splinter, split, spread, spread out,
   spring open, strawberry mark, sty, swing open, taint, tap, tear,
   tear open, throw open, track, trench, twist, valley, verruca,
   vesicle, void, vulnerable place, wadi, wale, warp, wart, weak link,
   weak point, weakness, weal, welt, wen, whitehead