رجس
Rijs
An evil deed, or a thing that God has prohibited.
What it means
Rijs is an Arabic word for a filthy or abominable thing, whether a wicked act or something God has forbidden. The Quran uses it of intoxicants, gambling, idol-stones and divining arrows, which it calls an rijs from the work of Satan and which believers are told to avoid (5:90). It also tells believers to avoid the rijs of idols (22:30). The word carries a sense of moral uncleanness, which is why it is applied to what harms the soul and the community. Muslims use it for what God has declared forbidden and corrupting.
Often misunderstood as
That it means only physical dirt, when it extends to forbidden and corrupting acts.
Term and Arabic as listed in Ismail al Faruqi, Toward Islamic English (International Institute of Islamic Thought, 1995), p. 33, listed as RIJS. The definition is restated here.