The crossword solution for the term 'Was a sound sleeper?' is SNORED, which is a 6 letter word. Snoring is a common symptom of sleep apnea, a disorder in which breathing is briefly and repeatedly interrupted during sleep. It can also be caused by other factors such as allergies, sinus problems, or even sleeping on your back. People who snore are often considered to be sound sleepers because they are able to sleep through the noise.