foil

英訳された三島由紀夫の金閣寺を読んでいます。
That summer the Golden Temple seemed to use the bad war news that reached us day after day as a sort of foil against which it shone more vividly than ever.
ここに出てきた "foil" は12/15/2009に取り上げているので覚えていなければならないのですが、アルミフォイルや刑事フォイル（スペルは違います）が頭に浮かぶので再度辞書を見直します。
・Oxford English Dictionary: A person or thing that contrasts with and so emphasizes and enhances the qualities of another: the earthy taste of grilled vegetables is a perfect foil for the tart bite of creamy goat cheese
・Vocabulary.com: You can serve as a foil to someone if you show them to be better than you by contrast. If you can't dance but your friend Lisa can, you can be a foil to Lisa's grace.
If you're having trouble remembering this definition, think about a shiny piece of tin foil. It reflects an image back to you, so if you're a foil to someone, their image is reflected off of you in a positive light. Your brother's mediocre grades might serve as a foil to your intelligence. As a verb, if you foil someone's plans or attempts to do something, you cause them to fail. Your brother will be really mad if you foil his plans to hide his mediocre report card from your parents.
ドラマには多くの場合、引き立て役がいるのでドラマを見る度に "foil" を思い出すことにしよう。