The word “luna” is likely familiar to you — it’s the Latin for “”moon,”” and we see it most clearly in the English adjective for anything related to the moon, “lunar.” (The words “lunacy” and “lunatic” were coined in the 16th century because it was believed that a certain type of intermittent insanity was related to the changes in the moon.) The word “lunate” is also related to the moon, but it specifically pertains to the crescent moon. “Lunate” is an adjective meaning “crescent-shaped,” and it’s commonly used in anatomy or botany to describe things with a crescent, or curved structure.