気孔[kikou] pore
空気孔[kuukikou] air pocket
孔子[koushi] Confucius
孔雀[kujaku] peafowl (inc. the male peacock, female peahen, and young peachick)
孔雀石[kujakuseki] malachite

孔雀妙王[kujakumyouou] Mayuri Vidya-raja
細孔[saikou] pore
多孔[takou] porous
通気孔[tsuukikou] vent

機関[karakuri] mechanism
アナログ計算機[anarogukeisanki] analog computer
エンジン発動機[enjinhatsudouki] engine
サーボ機構[saabokikou] servomechanism
シフト演算機構[shifutoenzankikou] shift arithmetic unit

ジェット機[jettoki] jet aeroplane
弾機[hatsujou] spring (e.g. coil, leaf)
ヒグス機構[higusukikou] Higgs mechanism (physics)
プロペラ機[puroperaki] propeller-driven aircraft
圧延機[atsuenki] rolling machine

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)