knuckle down片語動詞KK [ˋnʌkəl daʊn] /ˈnʌkəl daʊn/發音片語動詞1開始認真努力、專心用功、埋頭苦幹If you knuckle down now, you can still pass the exam.如果你現在開始認真用功,還是能通過考試。2著手專心做、埋頭投入常接 toShe finally knuckled down to writing her final report.她終於埋頭寫起期末報告。3屈服、讓步舊式He refused to knuckle down to their unreasonable demands.他拒絕對他們無理的要求屈服。