n. In anatomy, a foramen; specifically; one of certain foramina of the inner ear. See phrases below.n. In entom.: A transparent spot in an opaque surface, as in the wings of certain butterflies and mothsn. One of two perforations, covered with membrane, on the head of a cockroach, above the insertions of the antennæ. They have been regarded as rudimentary ocelli. See cut under Insecta.n. In surgery, an opening in a splint or immovable dressing to permit of inspection of the part or to relieve pressure.