umbilicus, vagina, anus, sphincter, speculum, cannula, cavity, rectum, posterior, chest cavity, ostia, tympanic membrane, vulva, sigmoid colon, incision, urethra, cloaca, labial, foramen, anal canal, canula, auricle, vas deferens, angulation, dural, obturator, scrotal, curette, suction, glans, anal, ureter, carotids, cautery, tube, ileocecal valve, commissure, nipple, spermatic cord, keyhole, nether region, diaphragm, bicuspid, stoma, plasty, perforations, dilator, penis, auditory canal, embolus, palatal, septum, fontanelle, tear duct, endotracheal tube, bunghole, alimentary canal, follicle, symphysis, inguinal canal, collet, inferior vena cava, glottis, ductus, bleb, tubal, annular, abdominal cavity, maxillary, outie, nostril, gland, stylet, superior vena cava, reamer, esophagus, tubercle, trepanning, venturi, sulcus, perineum, suprapubic, labia majora, uterine cavity, apertures, tragus, sprue, gullet, sigmoid, suprarenal, conceptus, anal sphincter, pores, peritoneum, impeller, annulus, axillary artery, acetabulum, intimal, diverticular, pedicle, orifices, aperture, ostium, opening, lumen, pore, meatus, slit, vestibule, nozzle, openings, canal, cusps, ampulla, cusp, inlet, electrode, flush, pressure, coaxial, hole, manometric, propeller, rectifier, rosette, aerodynamic, box, burner

arse, blastopore, cardia, cervix, external orifice, fenestra, fontanel, mouth, naris, os, pylorus, soft spot, spiracle, urethral orifice, uterine cervix, vent

aortic orifice, external orifice, hooded pitcher plant, sarracenia minor, spiracle, urethral orifice, vestibule of the vagina

passage, passageway