A Jacuzzi is a bathtub or small pool with jets that shoot streams of water and air bubbles, creating a swirling, massaging effect. The warm water and powerful jets help people relax sore muscles after sports or a long day. You might see a Jacuzzi on a hotel deck, at a health club, or in someone's backyard.

One of the Jacuzzi brothers designed the first whirlpool bath to help his young son, who had arthritis. The invention worked so well that the family started selling them, and their name became the word people use for any whirlpool bath, even ones made by other companies.

This happens with successful inventions: Kleenex, Band-Aid, and Velcro all started as specific brand names but became the common words for those products. When you say you're going to “sit in the Jacuzzi,” you might actually mean any whirlpool bath, not necessarily one made by the Jacuzzi company.

The correct pronunciation has three syllables and sounds like “juh-KOO-zee,” with the emphasis on the middle syllable.