彫心鏤骨[choushinrukotsu] laborious work
鏤める[chiribameru] to inlay

鏤骨[rukotsu] painstaking efforts
鏤刻[rukoku] carve

せん状骨[senjoukotsu] scaphoid bone (in wrist near thumb)
遺骨[ikotsu] remains
化骨[kakotsu] ossification
会厭軟骨[eennankotsu] epiglottis
がい骨[gaikotsu] skeleton

雁骨[kariganebone] scapula
気骨[kikotsu] (moral) backbone
侠骨[kyoukotsu] chivalrous spirit
胸骨[kyoukotsu] breastbone
筋骨[kinkotsu] muscles (sinews) and bones