A solid disk or cylinder that fits inside a hollow cylinder, and moves under pressure (as in an engine) or displaces fluid (as in a pump)

(botany) Any of the genus Lyonia of staggerbushes.

octamerous

Made of velvet. / Soft and delicate, like velvet; velvety. / (politics) Peaceful; carried out without violence; especially as pertaining to the peaceful breakup of Czechoslovakia.