The term SAILORS, INFORMALLY can be summarized by two crossword solutions: TARS (4 letters) and SALTS (5 letters). TARS is a slang term for sailors that originated in the Royal Navy in the 19th century. It is derived from the word 'TARPAULIN' which was a type of waterproof material used to make clothing for sailors. SALTS is another slang term for sailors that originated in the United States Navy in the 20th century. It is derived from the phrase 'salty dog, ' which was a term used to describe experienced sailors.