Appears 4 times in the Quran. (Root: قتل)
  1. So they put them to flight by Allah's permission. And Dawood slew Jalut, and Allah gave him kingdom and wisdom, and taught him of what He pleased. And were it not for Allah's repelling some men with others, the earth would certainly be in a state of disorder; but Allah is Gracious to the creatures.

  2. And it does not behoove a believer to kill a believer except by mistake, and whoever kills a believer by mistake, he should free a believing slave, and blood-money should be paid to his people unless they remit it as alms; but if he be from a tribe hostile to you and he is a believer, the freeing of a believing slave (suffices), and if he is from a tribe between whom and you there is a convenant, the blood-money should be paid to his people along with the freeing of a believing slave; but he who cannot find (a slave) should fast for two months successively: a penance from Allah, and Allah is Knowing, Wise.

  3. For this reason did We prescribe to the children of Israel that whoever slays a soul, unless it be for manslaughter or for mischief in the land, it is as though he slew all men; and whoever keeps it alive, it is as though he kept alive all men; and certainly Our messengers came to them with clear arguments, but even after that many of them certainly act extravagantly in the land.

  4. O you who believe! do not kill game while you are on pilgrimage, and whoever among you shall kill it intentionally, the compensation (of it) is the like of what he killed, from the cattle, as two just persons among you shall judge, as an offering to be brought to the Kaaba or the expiation (of it) is the feeding of the poor or the equivalent of it in fasting, that he may taste the unwholesome result of his deed; Allah has pardoned what is gone by; and whoever returns (to it), Allah will inflict retribution on him; and Allah is Mighty, Lord of Retribution.