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

蘇連[soren] (former) Soviet Union
ドイツ連邦共和国[doitsurenpoukyouwakoku] Federal Republic of Germany (former West Germany)
破天連[pateren] Portuguese Jesuits (in Japan in the 16th century)
一連[ichiren] series
引連れる[hikitsureru] to take along with

英連邦[eirenpou] Commonwealth of Nations (formerly British Commonwealth)
欧州連合[oushuurengou] European Union
家族連れ[kazokuzure] taking the family along
関連[kanren] relation
関連会社[kanrengaisha] associated company