annulus
n. வளைவடிவ அமைப்பு, குறிமறையினத்தாவரத்தில் சிதல் உறை விரிய உதவும் வளைய வடிவன்ன உயிர்மத்தொகுதி.
An"nu*lus, n.; pl. Annuli. Etym: [L.] 1. A ring; a ringlike part or space. 2. (Geom.) (a) A space contained between the circumferences of two circles, one within the other. (b) The solid formed by a circle revolving around a line which is the plane of the circle but does not cut it. 3. (Zoöl.) Defn: Ring-shaped structures or markings, found in, or upon, various animals.