機 (Kanji for machine)

Onyomi

KI	KEEP your crossbow machine away from me! I ain't do nothin'!

How many trees did it take to make that wooden machine?

機械(きかい)	machine ★★★★★ 機 (machine) + 械 (contraption) = 機械 (machine) A machine, particularly something with a motor in it which moves when activated. A computer is not a 機械 , but a robot arm is.
飛行機(ひこうき)	airplane ★★★★☆ 飛 (fly) + 行 (go) + 機 (machine) = 飛行機 (airplane)
機嫌(きげん)	mood ★★☆☆☆ 機 (machine) + 嫌 (eww!!) = 機嫌 (mood) mood (bad mood: 不機嫌!)
危機(きき)	social crisis ★★☆☆☆ 1/2 KANA 危 (dangerous) + 機 (machine) = 危機 (social crisis) a social crisis (oil crisis, global warming, etc.)
機会(きかい)	a chance ★☆☆☆☆ 機 (machine) + 会 (big meeting) = 機会 (a chance) a chance, as in, "I hope I will have a chance to go to Australia someday." or "This could be my only chance to see yo mama's huge collection of Rosie O'donnel pap-smears."