The term 'Sound of Sadness' can be represented by two crossword solutions: 'MOAN' (4 letters) and 'SNIFF' (5 letters). Moaning is a low, deep sound that is often associated with sadness or pain. It is usually made involuntarily and can be heard in both humans and animals. Sniffing is an action where one inhales air through the nose, often to detect a scent. It is also commonly associated with sadness, as people may sniffle when they are crying.