火山灰[kazanbai] volcanic ash
灰になる[haininaru] to be reduced to ashes
灰の水曜日[hainosuiyoubi] Ash Wednesday
灰押さえ[haiosae] ash leveler (use in a brazier)
灰押し[haioshi] ash leveler (use in a brazier)

灰殻[haigara] ashes
灰均し[hainarashi] ash leveler
灰皿[haizara] ashtray
灰受け[haiuke] ash pan

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