crystal clear

(archaic) Boards, planks, etc., that are free of knots.

(military) A temporary field hospital to treat and classify the sick and wounded.

plural of clearing station

(law, of a possession) In a condition of lawful outright ownership, without restrictions or encumbrances. / (law, of a person) Possessing such lawful outright ownership.

In a clear and easily understandable manner.

(idiomatic) There is no danger; one can freely pass through a region without risk of discovery.

(simile) Quite clear.

plural of clear title

plural of clear round