| cylindrical ostovâne-yi (#) Fr.: cylindrique    Of, pertaining to, or having the form of a cylinder. From L. cylindricus, from Gk. kylindrikos, see → cylinder; → -ic; → -al. | 
| cylindrical coordinates hamârâhâ-ye ostovâne-yi (#) Fr.: coordonnées cylindriques    A coordinate system for a point in space, using an origin (O) and three perpendicular axes (Ox, Oy, Oz), in which a point (P) in space is specified by three numbers ρ, φ, z. The two first numbers, ρ and φ, are → polar coordinates for the vertical projection of P on the xy-plane, and z is the vertical distance of P from the xy-plane. → cylindrical; → coordinate. | 
| cylindrical lens adasi-ye ostovâneyi  (#) Fr.: lentille cylindrique    A lens in which at least one surface is formed like a portion of a cylinder. Also called astigmatic lens. |