adj. 1 of, relating to, or determined by the moon. 2 concerned with travel to the moon and related research. 3 (of light, glory, etc.) pale, feeble. 4 crescent-shaped, lunate. 5 of or containing silver (from alchemists' use of luna (= moon) for 'silver'). lunar caustic silver nitrate, esp. in stick form. lunar cycle = METONIC CYCLE. lunar distance the angular distance of the moon from the sun, a planet, or a star, used in finding longitude at sea. lunar module a small craft used for travelling between the moon's surface and a spacecraft in orbit around the moon. lunar month 1 the period of the moon's revolution, esp. the interval between new moons of about 29« days. 2 (in general use) a period of four weeks. lunar nodes the points at which the moon's orbit cuts the ecliptic. lunar observation the finding of longitude by lunar distance. lunar orbit 1 the orbit of the moon round the earth. 2 an orbit round the moon. lunar year a period of 12 lunar months.
[ L lunaris f. luna moon ]