The term 'letter openers' refers to a tool used to open envelopes. The crossword solutions for this term are SIRS (4 letters), ABCD (4 letters), DEARS (5 letters), and SALUTATIONS (11 letters). These words are all forms of polite greetings that are typically found at the beginning of a letter. SIRS is an abbreviation of the phrase 'sirs and madams, ' ABCD stands for 'all the best, ' DEARS is a term of endearment, and SALUTATIONS is a formal greeting.