A letter closer is a person who is responsible for sealing and signing letters. The crossword solutions for the term letter closer are BEST (4 letters), YOURS (5 letters), SEAL (4 letters), XOXO (4 letters), ASEVER (6 letters), and SINCERELYYOURS (14 letters). BEST is an acronym for 'BEST Efforts and Sincere Thanks', YOURS is a polite way to end a letter, SEAL is an adhesive used to close envelopes, XOXO is a popular phrase used to express affection, ASEVER is an abbreviation for 'as ever', and SINCERELYYOURS is another polite way to end a letter.