observatory UK /əbˈzɜːvət(ə)ɹi/US /əbˈzɝvətɔɹi/ noun2 •A place where stars, planets and other celestial bodies are observed, usually through a telescope; also place for observing meteorological or other natural phenomena.The corporation of Harvard University have passed a vote closing the observatory in Cambridge to the public on Saturday evenings. — 1847 •A lookout (vantage point with a view of the surrounding area) formsobservatories