The term 'Prince or Princess' refers to a member of a ROYAL family, typically the son or daughter of a monarch. The two crossword solutions for this term are 'ROYAL' (5 letters) and 'HEIR' (4 letters). ROYAL is an adjective used to describe someone who is part of a monarchy, while HEIR is a noun that refers to a person who is entitled to inherit a throne, title, or property. Together, these two words provide a comprehensive description of a Prince or Princess.