Wikipedia logo The Simple English Wikipedia has an article on: Compound compound is on the Academic Word List. Pronunciation (UK) IPA (key): /ˈkɒmpaʊnd/ (US) enPR: kŏm'pound, IPA (key): /ˈkɑmpaʊnd/ Audio (US)(file) Noun Singular compound Plural compounds (countable) A compound is a material made of a number of other materials. The new chemical compound has far less smell than the original substance. There is a group of gases that do not easily form chemical compounds. (countable) A compound is a mixture. The new CD is a compound of North American rock music and Middle Eastern religious songs. (countable) A compound is a group of buildings surrounded by a fence or wall. Synonyms combination Antonyms element Verb Plain form compound Third-person singular compounds Past tense compounded Past participle compounded Present participle compounding (transitive) If something is compounded, it is added to. Her troubles were now compounded by the rain. (transitive) If interest is compounded, it is paid on earlier interest payments. Interest is compounded monthly. Synonyms combineWikiwand - on Seamless Wikipedia browsing. On steroids.