The term 'LION's Lair' is a metaphor for a place of refuge or a safe haven. It is often used to describe a place where one can go to escape the pressures of life. The crossword solutions for this term are DEN, which is a three-letter word meaning a small, secluded room or cave. This term is often used to describe a place of safety and security, which is why it is associated with the metaphor of a LION's lair.