1. The fundamental functional unit of compact bone. Osteons are roughly cylindrical structures that are typically several millimeters long and around 0.2mm in diameter. They are present in many bones of most mammals and some bird, reptile, and amphibian species. (wikipedia.org)
2. Any of the central canals, and surrounding bony layers, found in compact bone. (wiktionary.org)
3. A central canal containing blood capillaries and the concentric osseous lamellae around it occurring in compact bone. (biology-online.org)
Syn: Haversian system
Word origin: Before vowels oste-, word-forming element meaning “bone, bones,” from Greek osteon “bone.”