威勢 いせい Meanings Noun power; might; authority; influence spirits; vigor; vigour; energy; boldness Kanji 威 might. Read as イ. 勢 force. Read as セイ. Example sentences さあ、駆けつけ三杯、威勢よくぱっといきましょう。Anybody who shows up late has to chug! Common phrases 威勢がいい (いせいがいい) vigorous Words containing 威勢 威勢よく (いせいよく) with energy 威勢がいい (いせいがいい) vigorous 威勢のいい (いせいのいい) high-spirited Jinuma: Japanese Dictionary · Word lists