コスト効率[kosutokouritsu] cost effectiveness
圧電効果[atsudenkouka] piezoelectric effect
偉効[ikou] great effect
逆効果[gyakukouka] backfire
経済効果[keizaikouka] (positive) economic effect

効果[kouka] effect
効果音[koukaon] sound effect
効果的[koukateki] effective
効果覿面[koukatekimen] bring an immediate result on

安危[anki] fate
危うい[ayaui] dangerous
危うく[ayauku] barely
危ない[abunai] dangerous
危ながる[abunagaru] to be afraid of

危なっかしい[abunakkashii] dangerous
危ぶむ[ayabumu] to fear
危める[ayameru] to wound
危絵[abunae] suggestive or indecent picture
危害[kigai] injury