crystal clear Definition

crystal
noun

1. Colourless transparent quartz.

Form: rock crystal (also)
2. A crystal ball.
3a. A brilliant, highly transparent glass used for cut glass;
3b. Cut-glass articles.
4. A small piece of a solid that has a regular three-dimensional shape, and whose plane faces are arranged in a regular order and meet each other at specific angles.
5. chem.
Any solid substance consisting of a regularly repeating arrangement of atoms, ions or molecules.
6. elec.
A crystalline element, made of piezoelectric or semiconductor material, that functions as a transducer, oscillator, etc in an electronic device.

adj

1. Belonging or relating to, or made of, crystal.

Idiom: crystal clear

As clear or obvious as can be.

Etymology: 11c: from Latin crystallum, from Greek krystallos ice.