Pronunciation (US) IPA (key): /ˈpaʊɚfəl/ (UK) IPA (key): /ˈpaʊəfəl/ Audio (US)(file) Hyphenation: pow‧er‧ful Adjective Positive powerful Comparative more powerful Superlative most powerful Powerful is on the Academic Vocabulary List. If someone (or something) is powerful, they have much power. The king is a very powerful man. Big guns are powerful weapons. A tiger is powerful animal. The train has a powerful engine. This short entry needs someone to make it better. You can help Wiktionary by adding to it.Wikiwand - on Seamless Wikipedia browsing. On steroids.