悪循環[akujunkan] vicious circle
一環[ikkan] link (e.g. a part of a larger plan)
印環[inkan] signet ring (in medical contexts, e.g. signet ring cell)
円環[enkan] circle
花環[hanawa] wreath

環境[kankyou] environment
環境グループ[kankyouguruupu] environmental group
環境事業[kankyoujigyou] environmental business
環境庁[kankyouchou] Environment Agency
環境庁長官[kankyouchouchoukan] Director General of Environment Agency

御金[okane] money
金糸雀[kinshijaku] canary (esp. the island canary, Serinus canaria)
違約金[iyakukin] penalty for contract breach
一刻千金[ikkokusenkin] every moment is precious
一字千金[ichijisenkin] word of great value

一時金[ichijikin] lump sum
一時賜金[ichijishikin] lump-sum grant
引き金を引く[hikiganewohiku] to pull the trigger
引当金[hikiatekin] reserves
隠れ借金[kakureshakkin] hidden debts