- watch glass - laboratory glassware; a shallow glass dish used as an evaporating surface or to cover a beaker
--1 is a kind of dish
- crystal, watch crystal, watch glass - a protective cover that protects the face of a watch
--2 is a kind of protective covering, protective cover, protection
--2 is a part of watch, ticker - crystal, watch crystal, watch glass - a protective cover that protects the face of a watch