過激[kageki] extreme
過激派[kagekiha] radical party
感激[kangeki] deep emotion
急激[kyuugeki] sudden
矯激[kyougeki] radical

激臭[gekishuu] strong odor
激化[gekika] intensification
激減[gekigen] dropping sharply
激賞[gekishou] enthusiastic praise
激情[gekijou] violent emotion