See Also: annulus(dictionary)
Annulus(health)
annulus(medicine)
annulus iridis(medicine)
annulus ovalis(medicine)
annulus tympanicus(medicine)
annulus umbilicalis(medicine)
annulus urethralis(medicine)
periseptal annulus(medicine)
Annulus fibrosis(health)

annulus (iou)



annulus noun. . M16.
[Latin, late form of anulus dim. of anus ring (see ANUS).]
Chiefly Math. & Botany. A ring, a circle that is not filled in; spec. a partial veil forming a collar round the stalk in some agarics; the ring of thickened cells surrounding the sporangium of a fern.