The term 'shivery sound' can be described by two crossword solutions: BRR (3 letters) and BRRR (4 letters). BRR is an onomatopoeia that is used to describe a shivering sound, usually made by a person or animal. It is often used to express coldness or fear. BRRR is a variation of BRR, which is used to express a longer, more intense shivering sound. Both words are commonly used in literature and everyday speech to describe a sound associated with coldness or fear.