鈎虫[kouchuu] hookworm
鈎鼻[kagibana] hooked nose
毛鈎[kebari] (fishing) fly
鈎爪[kagizume] claw

鈎股弦の定理[koukogennoteiri] Pythagorean theorem
鈎股弦[koukogen] three sides of right triangle (minor cathetus, major cathetus & hypotenuse)
引目鈎鼻[hikimekagihana] style of drawing the human face, popular in the Heian period