An hourglass is a device that measures the passage of time. It is typically shaped like an inverted cone with a narrow waist in the middle, and consists of two glass bulbs connected by a narrow neck. The hourglass is filled with sand or other granular material, and as the sand passes through the neck, it measures the amount of time that has passed. The SHAPE of the hourglass is often used to describe the SHAPE of other objects, such as the body of a woman. The term 'TIMER' is also used to refer to an hourglass, as it is used to measure the passage of time.