The crossword solution for the term 'WHAT A LETTER NEEDS' is LEAST, which is a five-letter word. This term refers to the minimum amount of postage that is required to send a letter through the mail. The United States Postal Service requires a certain amount of postage to be affixed to a letter in order for it to be delivered. The amount of postage required depends on the size and weight of the letter, as well as the destination.