The Collaborative International Dictionary of English v.0.48:

Slit \Slit\, obs.
   3d. pers. sing. pres. of Slide. --Chaucer.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Slit \Slit\, v. t. [imp. & p. p. Slit or Slitted; p. pr. &
   vb. n. Slitting.] [OE. slitten, fr. sliten, AS. st[imac]tan
   to tear; akin to D. slijten to wear out, G. schleissen to
   slit, split, OHG. sl[imac]zan to split, tear, wear out, Icel.
   st[imac]ta to break, tear, wear out, Sw. slita, Dan. slide.
   Cf. Eclat, Slate, n., Slice.]
   1. To cut lengthwise; to cut into long pieces or strips; as,
      to slit iron bars into nail rods; to slit leather into
      straps.
      [1913 Webster]

   2. To cut or make a long fissure in or upon; as, to slit the
      ear or the nose.
      [1913 Webster]

   3. To cut; to sever; to divide. [Obs.]
      [1913 Webster]

            And slits the thin-spun life.         --Milton.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Slit \Slit\, n. [AS. slite.]
   A long cut; a narrow opening; as, a slit in the ear.
   [1913 Webster]

   Gill slit. (Anat.) See Gill opening, under Gill.
      [1913 Webster]

WordNet (r) 3.0 (2006):

slit
    n 1: a long narrow opening
    2: obscene terms for female genitals [syn: cunt, puss,
       pussy, slit, snatch, twat]
    3: a depression scratched or carved into a surface [syn:
       incision, scratch, prick, slit, dent]
    4: a narrow fissure
    v 1: make a clean cut through; "slit her throat" [syn: slit,
         slice]
    2: cut a slit into; "slit the throat of the victim"

Moby Thesaurus II by Grady Ward, 1.0:

286 Moby Thesaurus words for "slit":
   abrade, abysm, abyss, aggravated, amputate, aperture, arroyo, ax,
   bark, bezel, bisect, blemish, bloody, box canyon, breach, break,
   breakage, broach, broken, burn, burned, burst, busted, butcher,
   canal, canaliculate, canaliculated, canalize, canyon, carve,
   cavity, chafe, chamfer, chamfered, channel, channeled, chap, chase,
   chasm, check, checked, chimney, chink, chinky, chip, chipped,
   chisel, chop, claw, cleave, cleft, cleuch, clough, cloven, col,
   corduroy, corduroyed, corrugate, corrugated, corrugation, costate,
   coulee, couloir, crack, cracked, cranny, craze, crazed, crevasse,
   crevice, crimp, crimped, cut, cut apart, cut away, cut in two,
   cut off, cut open, cwm, dado, dadoed, damaged, defile, dehiscent,
   dell, deteriorated, dichotomize, dike, dispart, dissever, ditch,
   divaricate, divide, donga, draw, embittered, engrave, engraved,
   engraving, exacerbated, excavation, excise, fault, fissure,
   fissured, fissury, flaw, flume, flute, fluted, fluting, fly open,
   fracture, fray, frazzle, fret, furrow, furrowed, gall, gap, gape,
   gaping, gappy, gash, gashed, goffer, goffered, gorge, gouge,
   gouged, groove, grooved, gulch, gulf, gully, hack, halve, harmed,
   hew, hole, hurt, impaired, imperfect, in bits, in pieces,
   in shards, in shreds, incise, incised, incision, injure, injured,
   irritated, jigsaw, joint, kloof, knife, lacerate, lacerated, lance,
   lay open, leak, maim, make mincemeat of, mangled, maul,
   microgroove, moat, mutilate, mutilated, notch, nullah, ope, open,
   open up, opening, pare, part, pass, passage, pierce, pleat,
   pleated, plow, prune, puncture, quartered, rabbet, rabbeted,
   ragged, ravine, rend, rent, ribbed, rifle, rifled, rifling, rift,
   rime, rimose, rimulose, rip, rive, riven, ruck, run, rupture,
   ruptured, rut, rutted, rutty, savage, saw, scald, scalded, scale,
   scissor, scissure, scorch, scorched, score, scored, scotch, scrape,
   scratch, scratched, scuff, seam, separate, sever, severed,
   shattered, shredded, skin, slash, slashed, slice, slot, smashed,
   snip, splinter, splintered, split, sprain, spread, spread out,
   spring open, sprung, stab, stick, strain, streak, stria, striate,
   striated, striation, sulcate, sulcated, sulcation, sulcus, sunder,
   swing open, tap, tattered, tear, tear open, the worse for,
   throw open, torn, traumatize, trench, trough, troughed, valley,
   void, wadi, weakened, well-worn groove, whittle, worse, worse off,
   worsened, wound, wrench, wrinkle, wrinkled