To act in a manner highly contrary to; to counteract or contradict.(verb)
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Use "fly in the face of" in a sentence
"It may have been on Cain's part a kind of titanic attempt to fly in the face of Heaven's decree."
"In the seventh generation from Adam comes a man in the line of the Cainites who dares to fly in the face of this divine institution."
"Hunger, despite Jung, fear despite Sadger, and anger despite Freud, are just as primary, aboriginal and independent as sex, and we fly in the face of fact and psychic experience to derive them all from sex, although it is freely granted that in morbid cases each may take on predominant sex features."