The term 'Dress to the Nines, with 'UP'' is an idiom that means to dress in one's best clothing. The crossword solution for this term is TOG, which stands for a type of clothing - a toga. A toga is a garment worn in Ancient Rome, usually made of wool or linen and draped around the body. It was typically worn by men, but women also wore them on special occasions. The phrase 'Dress to the Nines, with 'UP'' is used to emphasize the importance of dressing well for a special occasion.