Overnight delivery is a service offered by many companies that allows customers to have their packages delivered within 24 hours. The term 'overnight delivery' can be abbreviated as 'DEW, ' which is the answer to the crossword puzzle. Overnight delivery is often used for time-sensitive items, such as medical supplies or documents that need to be signed and returned quickly. It is also used for items that are too large or too fragile to be sent through regular mail services.