Baize is a coarse woollen or cotton cloth, called "felt" in American English, often coloured red or green. It is often used on snooker and billiards tables (it is the green cloth that covers the top and is often referred to as 'the green baize'). As the surface finish for baize is not exceptional, it is generally not used for tables used on the professional circuit. Instead, worsted wool is preferred.
The term is related to the cloth term "bays" (sometimes under the heading "bays and says").