A prince is a male ruler or a male member of a monarch's or former monarch's family. Prince is also a title of nobility, often hereditary, in some European states. The female equivalent is a princess. The English word derives, via the French word prince, from the Latin noun prīnceps, from primus (first) and caput (head), meaning "the first, foremost, the chief, most distinguished, noble ruler, prince".

Princess is a title used by a female member of a monarch's family or by a female ruler. The male equivalent is a prince. Most often, the term has been used for the consort of a prince, or for the daughter of a monarch. A crown princess can be the heiress apparent to the throne or the spouse of the heir apparent.