definition of lunar
lunar. adj. 1. (Celestial Objects) of or relating to the moon. 2. (Celestial Objects) occurring on, used on, or designed to land on the surface of the moon: lunar module.3. (Celestial Objects) relating to, caused by, or measured by the position or orbital motion of the moon.4. (Elements & Compounds) of or containing silver.[C17: from Latin lÅ«nÄris, from lÅ«na the moon].. (Celestial Objects) occurring on, used on, or designed to land on the surface of the moon: lunar module. 3. (Celestial Objects) relating to, caused by, or measured by the position or orbital motion of the moon. 4. (Elements & Compounds) of or containing silver. [C17: from Latin lÅ«nÄris, from lÅ«na the moon].