Definition of cassettes:
(n) :
A small flat case containing magnetic tape on two reels, used to record and play back audio and video material.
(n) :
Any similar small cartridge, such as for a computer disk or cassette air conditioner.
(n) :
(photography) A lightproof container for photographic film.
(n) :
(cycling) A set of sprockets mounted onto a splined shaft on the freehub.
(n) :
(genetics) A modular DNA sequence encoding one or more genes for a single biochemical function.
(n) :
(ceramics) A saggar (ceramic container used in a kiln).