A nail treatment is a beauty service that involves the care and decoration of fingernails and toenails. The two crossword solutions for the term nail treatment are 'manicure' (8 letters) and 'mani' (4 letters). A manicure is a cosmetic beauty treatment for the hands and nails, which typically includes filing and shaping of the nails, treating the cuticles, and applying polish. A mani is a shortened version of the word manicure.