The term 'HOT TUB FEATURE' can be broken down into two crossword solutions: JET (3 letters) and EDDY (4 letters). A JET is a device that produces a powerful stream of water, usually used in hot tubs to provide a massage-like effect. An EDDY is a circular current of water that is created when a main current of water is obstructed. This feature is often found in hot tubs to provide a more relaxing experience.