1.That which girds, encircles, or incloses; a circumference; a belt; esp., a belt, sash, or article of dress encircling the body usually at the waist; a cestus. " Within the girdle of these walls." "Their breasts girded with golden girdles."
2.The zodiac; also, the equator. (Poetic) "From the world's girdle to the frozen pole." "That gems the starry girdle of the year."
3.(Jewelry) The line ofgreatest circumference of a brilliant-cut diamond, at which it is grasped by the setting.
4.(Mining) A thin bed or stratum of stone.
5.(Zool.) The clitellus of an earthworm.