noun
first knuckle joint
Refers to the joint closest to the fingertip, commonly used in contexts like finger injuries or measuring finger length.
バスケットボールで第一関節を突き指した。
I jammed my first knuckle joint playing basketball.
指の第一関節から第二関節までの長さを測る。
Measure the length from the first knuckle joint to the second knuckle joint of the finger.
Refers to the middle knuckle joint, while 第一関節 is the one closest to the fingertip.
Compound of 第一 (first) and 関節 (joint).