[n. of action f. ANNULATE.] The formation of rings or ring-like divisions; concr. a ring-like structure, a ring.
1829. [J. L. Knapp], Jrnl. Naturalist, 332. The whole body of the animal [hairworm] consists of numerous annulations.
1870. Rolleston, Anim. Life, Introd. 123. Their [worms’] bodies are … divided externally by annulation.
1872. Nicholson, Palæont., 271. The walls of the shell are … surrounded with numerous thickened rings or annulations.
