crystal

noun

1. 1. a clear, transparent mineral; esp., pure quartz
   2. a piece of such quartz cut in the form of an ornament
2. 1. a very clear, brilliant glass
   2. articles made of this glass, such as goblets, bowls, or other ware
3. ☆ the transparent protective covering over the face of a watch
4. anything clear and transparent like crystal
5. a solidified form of a substance in which the atoms or molecules are arranged in a definite pattern that is repeated regularly in three dimensions: crystals tend to develop forms bounded by definitely oriented plane surfaces that are harmonious with their internal structures
6. Radio, Elec. a piezoelectric body or plate, as of quartz, used to control very precisely the frequency of an oscillator or as a circuit element in a crystal filter or a body, often of Rochelle salt, used in a transducer, as in a crystal pickup or microphone

Etymology: altered (modeled on L) < ME & OFr cristal, OE cristalla < L crystallum, crystal, ice < Gr krystallos < kryos: see crude

adjective

1. of or composed of crystal
2. like crystal; clear and transparent
3. Radio of or using a crystal

noun

Etymology: see crystal