Noun, pl. foramina
1. Any opening. Foramina inside the body of humans and other animals typically allow muscles, nerves, arteries, veins, or other structures to connect one part of the body with another. (wikipedia.org)
2. An opening, an orifice; a short passage. (wiktionary.org)
3. A natural opening or perforation through a bone or a membranous structure. (wordnetweb.princeton.edu)
Word origin: From Latin foramen “hole, opening, aperture, orifice,” from forare “to pierce”.