The term 'CASTS A SPELL UPON' can be solved by the crossword solution 'HEXES', which is a five-letter word. HEXES are a type of magic spell that is used to cause harm or misfortune to another person. In some cultures, HEXES are believed to be powerful enough to bring about death. HEXES are often used in rituals and ceremonies, and they can be cast on an individual or a group of people. HEXES are also used to ward off evil spirits and protect against bad luck.