Santa's Bag is a term used to describe the large SACK that Santa Claus carries with him when delivering presents on Christmas Eve. It is often filled with toys, candy, and other gifts for children. The term 'Santa's Bag' can also be used to refer to the bag of tricks that Santa has up his sleeve to make sure that all the children get their presents. The crossword solution for this term is SACK, which is a four-letter word meaning a large bag made of cloth or leather, usually used for carrying things.