火燵掛布[kotatsugake] cover for kotatsu
火燵布団[kotatsubuton] cover for kotatsu
引火[inka] catching fire
引火温度[inkaondo] flash temperature
引火点[inkaten] flash point

曳火弾[eikadan] tracer bullet
煙火[enka] smoke and fumes (e.g. from cooking)
遠火[toobi] distant fire
下火[shitabi] burning low
下火になる[shitabininaru] to be under control

研鑽[kensan] diligent study
鑽り火[kiribi] striking sparks with flint and steel or by rubbing sticks together (usu. to start a fire)
鑽孔機[sankouki] boring machine
鑽り出す[kiridasu] to quarry

鑽孔[sankou] boring
鑽る[kiru] to start a fire (with wood-wood friction or by striking metal against stone)
自己研鑽[jikokensan] self-improvement
火鑽り[hikiri] hand drilling (to start a fire)