A portmanteau is a linguistic blend of two or more words, where parts of the words are combined to create a new term. This new word typically carries meanings from both original words. For example, the word brunch is formed from breakfast and lunch, representing a meal that combines elements of both. Portmanteaus are often used in popular culture and branding to create catchy names. Other examples include smog (from smoke and fog) and motel (from motor and hotel). These creative combinations can make language more dynamic and engaging.