Synonyms and related words :
aperture, boredom, broaching, cavity, chasm, check, clearing, cleft, crack, dehisce, dehiscence, disclosure, doldrums, doze, drowse, ennui, fenestra, fistula, fontanel, foramen, gap, gape, gaping, gat, gulf, hang open, hiatus, hole, hollow, inlet, interval, lacuna, laying open, leak, nap, opening, opening up, orifice, oscitancy, oscitate, oscitation, outlet, pandiculation, passageway, pore, slot, snooze, space, split, stoma, the gapes, throwing open, uncorking, unstopping, yaw, yawning