に就て[nitsuite] concerning
に就き[nitsuki] because of
去就[kyoshuu] committing one's self
就いては[tsuiteha] in line with this
就きましては[tsukimashiteha] in line with this

就く[tsuku] to ascend (the throne)
就ける[tsukeru] to install (a king, emperor, etc.)
就学[shuugaku] entering school
就学義務[shuugakugimu] compulsory school attendance
就学児童[shuugakujidou] school child

黄鉄鉱[outekkou] iron pyrites
可鍛鉄[katantetsu] malleable iron
狭軌鉄道[kyoukitetsudou] narrow-gauge railway
近鉄[kintetsu] Kinki Nippon Tetsudou (railway co.)
剣付き鉄砲[kentsukideppou] fixed bayonet

甲鉄[koutetsu] armor
甲鉄艦[koutetsukan] armored ship
甲鉄板[koutetsuban] armor plate
鋼鉄[koutetsu] steel
国鉄[kokutetsu] national railway (esp. Japan National Railways)