Yeltsin was a useful foil.
To Mr. Pataki's aides, the majority leader was a useful foil whose sincere but sometimes wild-eyed desire to wipe away rent control made the Governor seem moderate by comparison.
Yet in their rigid allegiance to the grid, these projects are a useful foil to the more adventurous work.
A useful foil for bright flowers.
And he has also emerged as a useful political foil for President Bush.
Miss Yeager's sylph had a great deal of hip swaying and yet her mannered coquettishness was a useful foil to Mr. Bocca's simplicity.
A wagon full of belongings made a useful foil.
More likely overly ambitious--but even then, he could have proved a useful foil for us, to keep the king's attention whiles we came up behind.
Zimivic could never be called an ally, but he might make a useful foil.
All three presidential bad boys have found an especially useful foil in the Bush administration, with its eager resort to American might.