knuckle: [14] Knuckle originally denoted the rounded end of a bone at a joint, which sticks out when you bend the joint. This could be at any joint, including the elbow, the knee and even the joints of the vertebrae; only gradually did it become specialized to the finger joints. The word probably came from Middle Low German kn?kel (or a relative of it), which appears to have meant etymologically ‘little bone’. Knuckle down, in the sense ‘begin to work hard and conscientiously’, comes from the game of marbles, where players have to put their knuckles on the ground when shooting a marble with the thumb.
knuckle (n.)
mid-14c., knokel "finger joint; any joint of the body, especially a knobby one; morbid lump or swelling;" common Germanic (cognates: Middle Low German kn?kel, Middle Dutch cnockel, German kn?chel), literally "little bone," a diminutive of Proto-Germanic root *knuk- "bone" (compare German Knochen "bone).
As a verb from 1740, originally in the game of marbles. To knuckle down "apply oneself earnestly" is 1864 in American English, extended from marbles (putting a knuckle on the ground in assuming the hand position preliminary to shooting); to knuckle under "submit, give in" is first recorded 1740, supposedly from the former more general sense of "knuckle" and here meaning "knee," hence "to kneel." The face-busting knuckle-duster is from 1858 (a duster was a type of protective coat worn by workmen).
例文
1. The United States，he said，did not knuckle under to demands.
彼は、米国は他人の要求に屈しないと言った。
2.David Seaman was back in the Arsenal goal after breaking a knuckle .
デービッド?シーマンは指関節を骨折した後、アーセナルのゴール前に戻った。
3.It is arguable whether the rebels will knuckle under.
反逆者が投降するかどうかはまだ確定できていない。
4.The only thing to do was knuckle down and get on with some serious hard work.
唯一できることは、努力して仕事を始め、しっかりと成績を出すことです。
5.He managed to knuckle down to his lessons long enough to pass his examination.