The term 'sailor, in slang' can be summarized by two crossword solutions: TAR (3 letters) and GOB (3 letters). TAR is an abbreviation for a sailor, derived from the word 'tarred, ' which was used to describe sailors in the 18th century. GOB is another slang term for a sailor, derived from the word 'GOB, ' which was used to describe a sailor's mouth. Both terms are still used today to refer to sailors in a casual or humorous way.