THESAURUS
Cleft
abysm, abyss, alienation, aperture, arroyo, bifurcated, bisected, blaze, box canyon, branched, branching, breach, breach of friendship, break, breakage, broaching, burst, canyon, cavity, chap, chasm, check, chimney, chink, chinky, chip, clearing, cleavage, cleuch, clough, clove, cloven, col, coulee, couloir, crack, cracked, cranny, crena, crevasse, crevice, cut, cwm, defile, dehiscent, dell, depression, dichotomous, dike, dimidiate, disaffection, disclosure, disfavor, disruption, disunion, disunity, ditch, divergence, divided, dividedness, division, donga, draw, estrangement, excavation, falling-out, fault, fenestra, fissure, fissured, fissury, fistula, flaw, flume, fontanel, foramen, forked, forking, fracture, furrow, gap, gape, gaping, gappy, gash, gat, gorge, groove, gulch, gulf, gully, hack, halved, hiatus, hole, hollow, in pieces, in shreds, incision, indentation, inlet, interval, jag, jog, joggle, joint, kerf, kloof, lacerate, lacerated, lacuna, laying open, leak, mangled, moat, mutilated, nick, nock, notch, nullah, open rupture, opening, opening up, orifice, outlet, pass, passage, passageway, pore, quartered, ragged, ramified, ravine, recall of ambassadors, rent, rift, rime, rimose, rimulose, rip, riven, rupture, scale, schism, scissure, score, scotch, seam, separation, severed, shredded, slash, slice, slit, slot, space, splinter, splintered, split, stoma, tattered, tear, throwing open, torn, trench, uncorking, unstopping, valley, void, wadi, yawn
ROGET THESAURUS
Cleft
bisection
N
bisection, bipartition, dichotomy, subdichotomy, halving, dimidiation, bifurcation, forking, branching, ramification, divarication, fork, prong, fold, half, moiety, bisected, cloven, cleft, bipartite, biconjugate, bicuspid, bifid, bifurcous, bifurcate, bifurcated, distichous, dichotomous, furcular, semi-, demi-, hemi.
Interval
N
interval, interspace, separation, break, gap, opening, hole, chasm, hiatus, caesura, interruption, interregnum, interstice, lacuna, cleft, mesh, crevice, chink, rime, creek, cranny, crack, chap, slit, fissure, scissure, rift, flaw, breach, rent, gash, cut, leak, dike, ha-ha, gorge, defile, ravine, canon, crevasse, abyss, abysm, gulf, inlet, frith, strait, gully, pass, furrow, abra, barranca, barranco, clove, gulch, notch, yawning gulf, hiatus maxime, hiatus valde deflendus, parenthesis, void, incompleteness, period, interim (time), with an interval, far between, breachy, rimose, rimulose, at intervals, longo intervallo.