Orifice

n.

1.

A mouth or aperture, as of a tube, pipe, etc.; an opening; as, the orifice of an artery or vein; the orifice of a wound. Etna was bored through the top with a monstrous orifice. - Addison.

Noun

1.

orifice - an aperture or hole opening into a bodily cavity; "the orifice into the aorta from the lower left chamber of the heart" Synonyms: porta, opening

aperture, broaching, cavity, chasm, check, clearing, cleft, crack, disclosure, fenestra, fistula, fontanel, foramen, gap, gape, gat, gulf, hiatus, hole, hollow, inlet, interval, lacuna, laying open, leak, opening up, outlet, passageway, pore, space, split, stoma, throwing open, uncorking, unstopping, yawn