Main Entry: ¹foil

Pronunciation: \ˈfȯi(-ə)l\

Function: transitive verb

Etymology: Middle English, alteration of fullen to full cloth, from Anglo-French foller — more at full

Date: 14th century

1 obsolete : trample
2 a : to prevent from attaining an end : defeat <always able to foil her enemies> b : to bring to naught : thwart <foiled the plot>

synonyms see frustrate