razor-sharp
adjective uk/ˌreɪ.zəˈʃɑːp/ us/ˌreɪ.zɚˈʃɑːrp/
(SHARP)
极锋利的；非常锐利的
extremely sharp
These animals have razor-sharp teeth. 这些动物长有非常尖利的牙齿。
(CLEVER)
非常敏锐的;犀利的
If you describe someone or someone's mind as razor-sharp, you mean that that person thinks very clearly and quickly.
She's got a razor-sharp mind. 她头脑敏锐。