鋭い
するどい · surudoi · JLPT N3 · i-adj
sharp
🔪 Sue, rude? Oi! — a sharp, pointed reply
The kanji 鋭 has the metal radical 金 on its left, because blades and points are made of metal. Like English 'sharp', it can also describe a mind or a remark: 鋭い質問 means a sharp question.