Cranny

Noun

 * 1) A small, narrow opening, fissure, crevice, or chink, as  in a wall, or other substance.
 * 2) A tool for forming the necks of bottles, etc.

Thesaurus
abysm, abyss, alcove, arroyo, asylum, bay, bezel, bolt-hole, box canyon, breach, break, cache, canyon, carrel, cavity, chamfer, chap, chase, chasm, check, chimney, chink, cleft, cleuch, clough, col, concealment, corner, corrugation, coulee, couloir, cove, cover, covert, coverture, crack, crevasse, crevice, cubby, cubbyhole, cubicle, cut, cwm, dado, dark corner, defile, dell, den, dike, ditch, donga, draw, dugout, engraving, excavation, fault, fissure, flaw, flume, flute, fluting, foxhole, fracture, funk hole, furrow, gap, gape, gash, gorge, gouge, groove, gulch, gulf, gully, hideaway, hideout, hidey hole, hiding, hiding place, hole, incision, joint, kloof, lair, leak, microgroove, moat, niche, nook, notch, nullah, opening, oriel, pass, passage, rabbet, ravine, recess, refuge, rent, retreat, rifling, rift, rime, roomlet, ruck, rupture, rut, sanctuary, scissure, score, scratch, seam, secret place, slit, slot, snuggery, split, stash, streak, stria, striation, sulcation, sulcus, trench, undercovert, valley, void, wadi, well-worn groove, wrinkle