The term 'FUSSES OVER ONE'S APPEARANCE' can be summarized by the crossword solution 'PREENS, ' which is a 6-letter word. Preening is a behavior in which an animal or person cleans, arranges, and adjusts their feathers, fur, or clothing to improve their appearance. It is often seen in birds, but humans may also engage in preening behaviors such as combing their hair or adjusting their clothing.