御古[ofuru] used article (esp. clothes)
手古摺る[tekozuru] to have much trouble
土耳古[toruko] Turkey
下稽古[shitageiko] rehearsal
懐古[kaiko] recalling the old days

擬古[giko] imitation of classical styles
擬古文[gikobun] classical style
稽古[keiko] practice
遠古登点[wokototen] marks to aid in reading Chinese classics
古え[inishie] antiquity

アナログデジタル変換器[anarogudejitaruhenkanki] analog-digital converter
圧搾器[assakuki] compression
圧力調整器[atsuryokuchouseiki] pressure regulator
安全器[anzenki] safety device
安定器[anteiki] stabilizer

医療器械[iryoukikai] medical appliances
育雛器[ikusuuki] breeder
化学兵器[kagakuheiki] chemical weapons
化学兵器禁止条約[kagakuheikikinshijouyaku] chemical weapons ban treaty
加減抵抗器[kagenteikouki] rheostat