crystal clear, be

be crystal clear

1. Of a thing or image, to be strikingly clear or clean. The picture on this new high-definition TV is crystal clear! The skies at the top of the mountain were just crystal clear.
2. Of information or communication, to be very easy to understand and not vague or ambiguous. A: "You have to drop this package off by 5 PM sharp, or it won't get delivered. Is that clear?" B: "Yep, it's crystal clear." A good lecturer is crystal-clear in class, but a great one makes the lessons engaging too.
See also: clear, crystal
Farlex Dictionary of Idioms.

crystal clear, be

Also, be clear as crystal. Be easy to understand, have a very obvious meaning. For example, The directions for installing the door are crystal clear, or Her intentions are clear as crystal. Allusions to crystal's very high degree of transparency have been made since the 15th century.
See also: crystal
The American Heritage® Dictionary of Idioms by Christine Ammer.
See also:
  • be crystal clear
  • crystal clear
  • clear (something) with (someone)
  • clear with
  • clear from some place
  • clear (something) from (something)
  • (as) clear as vodka
  • as clear as vodka
  • clear as vodka
  • vodka