The term 'Brief Letter' is a type of communication that is shorter than a standard letter. It is usually used to convey a simple message or to provide a quick response to a question. A brief letter typically contains only a few sentences and is often written in a more informal style than a standard letter. The crossword solutions for the term 'Brief Letter' are 'NOTE', which is a four-letter word. A NOTE is a short written message, usually on paper, that is used to communicate information quickly and informally.