mare UK /mɛə/US /mɛɚ/noun 4/ˈmɑɹ.eɪ/ noun 2forms 2phrases 1 noun4 •An adult female horse. •(slang, offensive) A foolish woman.The silly mare phoned your mother, talking about applying for a mortgage, and we don't want that, do we? — 2007 •(UK, informal) A nightmare; a frustrating or terrible experience.I'm having a complete mare today. •(no longer used, historical) A type of evil spirit formerly thought to sit on the chest of a sleeping person; also, the feeling of suffocation felt during sleep, attributed to such a spirit. mare /ˈmɑɹ.eɪ/ noun2 •A large, dark plain, which may have the appearance of a sea, such as those on the Moon. •On Saturn's moon Titan, any of several lakes which are large expanses of what is thought to be liquid hydrocarbons.Kraken Mare (a lake of liquid hydrocarbons on Titan which is slightly larger than the Caspian Sea) formsmares · maria Phrases with mare shanks' mareOne's own feet used for walking.