I. ˈkris-t ə l noun
Etymology: Middle English cristal, from Anglo-French, from Latin crystallum, from Greek krystallos — more at crust
Date: 13th century
1. : quartz that is transparent or nearly so and that is either colorless or only slightly tinged
2. : something resembling crystal in transparency and colorlessness
3. : a body that is formed by the solidification of a chemical element, a compound, or a mixture and has a regularly repeating internal arrangement of its atoms and often external plane faces
4. : a clear colorless glass of superior quality ; also : objects or ware of such glass
5. : the glass or transparent plastic cover over a watch or clock dial
6. : a crystalline material used in electronics as a frequency-determining element or for rectification
7. : ice 7 ; broadly : methamphetamine in any form when used illicitly
II. adjective
Date: 14th century
1. : consisting of or resembling crystal : clear , lucid
2. : relating to or using a crystal
a crystal radio receiver