Sharpness
noun, な adjective
Something that is sharp will benefit from its sharpness, since that's all it has, really.
This is a jukugo word that uses the on'yomi readings of the kanji. You should be able to read this on your own.
通り魔は、鋭利な刃物で私の全身を切りつけた。
The random attacker slashed at my body with a sharp knife.