The word(s) "impiety" appears 6 time(s) in 6 verse(s) in Quran in Abdullah Yusuf Ali translation.

(1) Forbidden to you (for food) are: dead meat, blood, the flesh of swine, and that on which hath been invoked the name of other than Allah; that which hath been killed by strangling, or by a violent blow, or by a headlong fall, or by being gored to death; that which hath been (partly) eaten by a wild animal; unless ye are able to slaughter it (in due form); that which is sacrificed on stone (altars); (forbidden) also is the division (of meat) by raffling with arrows: that is impiety. This day have those who reject faith given up all hope of your religion: yet fear them not but fear Me. This day have I perfected your religion for you, completed My favour upon you, and have chosen for you Islam as your religion. But if any is forced by hunger, with no inclination to transgression, Allah is indeed Oft-forgiving, Most Merciful.

(2) Eat not of (meats) on which Allah's name hath not been pronounced: That would be impiety. But the evil ones ever inspire their friends to contend with you if ye were to obey them, ye would indeed be Pagans.

(3) They said, "Who has done this to our gods? He must indeed be some man of impiety!"

(4) Such as fear not the meeting with Us (for Judgment) say: "Why are not the angels sent down to us, or (why) do we not see our Lord?" Indeed they have an arrogant conceit of themselves, and mighty is the insolence of their impiety!

(5) Or who is there that can provide you with Sustenance if He were to withhold His provision? Nay, they obstinately persist in insolent impiety and flight (from the Truth).

(6) Behold, the most wicked man among them was deputed (for impiety).