Word parts sudden + -ly Pronunciation IPA (key): /ˈsʌdn̩li/ Audio (US)(file) Adverb Positive suddenly Comparative more suddenly Superlative most suddenly If something happens suddenly, it happens very quickly when you don't expect it to happen. My son had been sitting in the chair beside me. Then, suddenly, I realised he was gone. Wikiwand - on Seamless Wikipedia browsing. On steroids.Remove ads