The term 'Post-Christmas Event' can be summarized by two crossword solutions: SALE (4 letters) and RETURN (6 letters). After Christmas, many stores offer sales on items that were not purchased during the holiday season. This is a great opportunity for shoppers to get discounted prices on items they may have wanted but were unable to purchase. Additionally, many stores also offer returns on items that were purchased during the holiday season. This allows customers to exchange or RETURN items that may not have been suitable for their needs.