noun
anatomy : a ringlike ligament or band of fibrous tissue encircling a part:
a. : any of the transverse bands holding in place the extensor and flexor tendons of the wrist and ankle
b. : a strong band of fibers surrounding the head of the radius and retaining it in the radial notch of the ulna — called also orbicular ligament
c. : any of certain strengthening bands of the tendon sheaths of the digits
d. : a ring attaching the base of the stapes to the fenestra vestibuli