- a curved glass disc that covers the dial of a watch
- a similarly shaped piece of glass used in laboratories for evaporating small samples of a solution, etc
Examples from the Web for watch-glass
A bit of the culture is removed and placed in a watch-glass of water.The Fundamentals of Bacteriology
Charles Bradfield Morrey
The edges are now ground off, and the watch-glass is complete.
A little of the supernatant ether is now removed to a small glass capsule or watch-glass, and allowed to evaporate spontaneously.
In form, it is circular, convexo-concave, and resembles a watch-glass.
There's no more glass about you than there is about me—and that is my watch-glass.