A spa is a fancy hotel or resort, especially one that offers health and beauty treatments or is located near a natural mineral spring. If you like being pampered, you might treat yourself to a day at a spa.
You might go to a spa to get a massage and sit in a sauna, or to visit the naturally warm springs in Sonoma, California or Saratoga Springs, New York. The springs themselves are often called spas, and as a result even a Jacuzzi bathtub with underwater jets is sometimes referred to as a spa. The word comes from the town of Spa, Belgium, which has been known for its mineral springs since the 15th century.