consisting of or containing or of the nature of crystals; "granite is crystalline"
transmitting light; able to be seen through with clarity; "the cold crystalline water of melted snow"; "crystal clear skies"; "could see the sand on the bottom of the limpid pool"; "lucid air"; "a pellucid brook"; "transparent crystal"
distinctly or sharply outlined; "crystalline sharpness of outline"- John Buchan
impervious to pleas, persuasion, requests, reason; "he is adamant in his refusal to change his mind"; "Cynthia was inexorable; she would have none of him"- W.Churchill; "an intransigent conservative opposed to every liberal tendency"
(bridge) a playing card with a value sufficiently high to insure taking a trick in a particular suit; "if my partner has a spade stopper I can bid no trump"
close or secure with or as if with a stopper; "She stoppered the wine bottle"; "The mothers stoppered their babies' mouths with pacifiers"