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

懐旧[kaikyuu] recalling the old days
旧ソ連[kyuusoren] former Soviet Union
旧悪[kyuuaku] past misdeeds
旧衣[kyuui] worn-out clothes
旧詠[kyuuei] ancient poems

旧怨[kyuuen] old grudge
旧縁[kyuuen] old relationship
旧恩[kyuuon] old favors
旧仮名遣[kyuukanazukai] former (i.e. before the post-WWII reforms) kana usage in writing the readings of kanji