The mare galloped across the field with her foal following closely behind.
A large, dark basaltic plain on the Moon or another planetary body, formed by ancient volcanic eruptions. Mare Imbrium is one of the most prominent maria visible from Earth.
A difficult, troublesome, or unpleasant situation; a nightmare (informal, chiefly British). The train delays were a complete mare, and we arrived two hours late.
An evil spirit or goblin in folklore thought to torment sleepers by sitting on their chests and bringing bad dreams (archaic). Medieval texts warn of the dreaded mare that steals peaceful rest from villagers.