1.
Water that is crystal clear is absolutely clear and transparent like glass.
The cliffs, lapped by a crystal-clear sea, remind her of Capri.
ADJ
2.
If you say that a message or statement is crystal clear , you are emphasizing that it is very easy to understand.
The message is crystal clear–if you lose weight, you will have a happier, healthier, better life...
ADJ : usu v-link ADJ [ emphasis ]