The term 'Be Silently Furious' can be represented by the crossword solution SEETHE, which is a six-letter word. SEETHE is a verb that means to be filled with or express strong emotion, such as anger, without speaking. It is often used to describe someone who is so angry that they are unable to express it verbally. Therefore, the phrase 'Be Silently Furious' can be interpreted as being so angry that one cannot express it through words.