Meaning

• A solid composed of an array of atoms or molecules possessing long-range order and arranged in a pattern which is periodic in three dimensions.

• A piece of glimmering, shining mineral resembling ice or glass.

• A fine type of glassware, or the material used to make it.

• Crystal meth: methamphetamine hydrochloride.

• The glass over the dial of a watch case.

Meaning

• Very clear.

  ""Do I make myself clear?" / "Crystal.""