gray Noun A penny with a tail on both sides, used for cheating. (Reference: Sidney J. Baker, "The Australian Language", second edition, 1966, chapter XI section 3, page 243.)
gray Noun an extraterrestrial creature with gray skin, bulbous black eyes, and an enlarged head.
gray Verb To become gray or cause to become gray.
gray Noun In the International System of Units, the derived unit of absorbed dose of radiation (radiation absorbed by a patient); one joule of energy absorbed per kilogram of the patient's mass. Symbol: "Gy"