Decay – English Flashcard for Decay for IELTS Updated: July 31, 2019 by Dr. Mohammad Hossein Hariri AslDecay Decay (noun & verb) /dɪˈkeɪ/to destroy something or be destroyed over time either naturally or artificially – decompose – grow moldy – crumble – decline:Keep the meat in the fridge; or else, it will decay soon.