The word "lunarnaut" refers to someone who travels or explores the moon. However, there are a few other words that can be used as synonyms to this term. One of them is "moonwalker," which refers to the astronauts who have had the chance to walk on the moon. Another synonym for "lunarnaut" is "moon explorer." This term is used to describe anyone who is involved in the exploration and study of the moon, whether it be through scientific research or space missions. Lastly, "lunatic" can be considered a synonym for "lunarnaut," although it has a somewhat negative connotation and is not usually used in an official context.