n (chiefly|US|ufology) an extraterrestrial creature with grayish skin, bulbous black eyes, and an enlarged head.
n (two-up|lang=en) A penny with a tail on both sides, used for cheating.Sidney J. Baker, The Australian Language, second edition, 1966, chapter XI section 3, page 243
n 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