Synonyms and related words :
air hole, annulet, armhole, blowhole, bullet-hole, bunghole, circlet, cringle, deadeye, eye, gasket, grommet, guide, keyhole, knothole, loop, loophole, manhole, mousehole, peephole, pigeonhole, pinhole, placket, placket hole, porthole, punch-hole, ringlet, roundlet, spiracle, tap, vent, venthole