The crossword solution for the term SUITABLE LETTER is TEE, which is a three-LETTER word. TEE is a golfing term that refers to a small wooden or plastic peg used to hold a ball in place for the first shot of a hole. It is also used in other sports such as cricket and baseball. In addition, TEE is also used as an acronym for many different things, such as 'Technology, Entertainment, and Electronics' or 'Transportation, Energy, and Environment'.