Sharpness
Quick Witted, Keenness
noun, な adjective
Someone on sharp alert has a sharpness about them. They are quick witted and have a strong keenness to them.
This word is formal and literary.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
その犬の鋭敏な嗅覚は、何人もの麻薬密売人を捕らえました。
That dog’s keen nose caught so many drug dealers.