Human anatomy
* '' Anulus fibrosus disci intervertebralis'', spinal structure * Annulus of Zinn, a.k.a. annular tendon or ''anulus tendineus communis'', around the optic nerve * Annular ligament (disambiguation) * ''Digitus anularis'', a.k.a.Other
* Annulus (construction), outer gear ring in an epicyclic gearing * Annulus (botany), structure on fern and moss sporangia * Annular lake, a ring-shaped lake caused by meteor impact * Annulus (mathematics), the shape between two concentric circles * Annulus (mycology), structure on mushroom * Annulus (firestop), site of construction issue * Annular piston, a ring-shaped piston * Annulus (well), void between concentric cylinders * Annular blowout preventer, device for sealing oil and gas wells * Annulation, type of ring-producing chemical reactionSee also
* * * Annulet (disambiguation) * Annular eclipse * Annular tropical cyclone * Annular combustor, design option in engine * Ring (disambiguation) {{disambiguation