The word(s) "infidelity" appears 4 time(s) in 4 verse(s) in Quran in Abdullah Yusuf Ali translation.

(1) Quite a number of the People of the Book wish they could Turn you (people) back to infidelity after ye have believed, from selfish envy, after the Truth hath become Manifest unto them: But forgive and overlook, Till Allah accomplish His purpose; for Allah Hath power over all things.

(2) It is not for such as join gods with Allah, to visit or maintain the mosques of Allah while they witness against their own souls to infidelity. The works of such bear no fruit: In Fire shall they dwell.

(3) O ye who believe! take not for protectors your fathers and your brothers if they love infidelity above Faith: if any of you do so, they do wrong.

(4) And there are those who put up a mosque by way of mischief and infidelity - to disunite the Believers - and in preparation for one who warred against Allah and His Messenger aforetime. They will indeed swear that their intention is nothing but good; But Allah doth declare that they are certainly liars.