Consisting of crystal.Relating or pertaining to crystals or crystallization.Formed by crystallization; of the nature of a crystal, especially as regards its internal structure, cleavage, etc.: opposed to amorphous.Resembling crystal; pure; clear; transparent; pellucid: specifically applied in anatomy to several structures, as the crystalline humor, cones, etc. See below.In entomology, reflecting light like glass: specifically applied to the ocelli or simple eyes when they are apparently colorless, resembling glass.n. A crystallized rock, or one only partially crystallized, as granite.