The term 'could' can be expressed in a variety of ways in crossword puzzles. The three-letter solution is 'MAY, ' which is used to express possibility or permission. The five-letter solution is 'MIGHT, ' which is similar to 'MAY' but is used to express a greater degree of uncertainty. The four-letter solution is 'itbe, ' which is an informal way of saying 'it could be.' Finally, the nine-letter solution is 'wasableto, ' which is a contraction of 'was able to, ' which is used to express the ability to do something in the past.