The term 'crossed letter' is a type of letter that is written with two sets of handwriting, usually by two different people. The term is often used in reference to letters written between two people who are in a romantic relationship. In this particular crossword, the solution for the term 'crossed letter' is TEE, which is an abbreviation for the word 'TELEGRAM'. A TELEGRAM is a type of communication that was popular in the 19th and early 20th centuries, where messages were sent via telegraph lines.