زنا
Zināʾ
Sexual intercourse outside marriage, which the Quran forbids and surrounds with strict conditions of proof.
What it means
“Do not come near adultery; it is an indecency and an evil way” (17:32). The Quran prescribes a hundred lashes for each offender (24:2). It requires four witnesses, and punishes with eighty lashes anyone who accuses a chaste person without them (24:4). A husband who charges his wife without witnesses swears oaths, and she may swear in reply (24:6–9).
Often misunderstood as
That Islam kills people on suspicion of adultery.
What the sources say
Stoning is not in the Quran. The majority of jurists hold it applies to a married offender, from reports of the Prophet’s own cases, while some early and modern scholars hold only the Quranic penalty applies. The evidence required, four eye-witnesses of the act itself, is almost never met, and the Prophet turned away from Maiz and the woman of Ghamid, who confessed, several times before ordering punishment (Sahih Muslim). Jurists derived the rule that penalties are waived where there is doubt.
Term and Arabic as listed in Ismail al Faruqi, Toward Islamic English (International Institute of Islamic Thought, 1995), p. 34, listed as ZINĀ. The definition is restated here.