What does « Sin » mean in the Quran?

And remember Allah during [specific] numbered days. Then whoever hastens [his departure] in two days - there is no sin upon him; and whoever delays [until the third] - there is no sin upon him - for him who fears Allah. And fear Allah and know that unto Him you will be gathered.

And when it is said to him, "Fear Allah," pride in the sin takes hold of him. Sufficient for him is Hellfire, and how wretched is the resting place.

They ask you about wine and gambling. Say, "In them is great sin and [yet, some] benefit for people. But their sin is greater than their benefit." And they ask you what they should spend. Say, "The excess [beyond needs]." Thus Allah makes clear to you the verses [of revelation] that you might give thought.

And if you are on a journey and cannot find a scribe, then a security deposit [should be] taken. And if one of you entrusts another, then let him who is entrusted discharge his trust [faithfully] and let him fear Allah, his Lord. And do not conceal testimony, for whoever conceals it - his heart is indeed sinful, and Allah is Knowing of what you do.

And let not those who disbelieve ever think that [because] We extend their time [of enjoyment] it is better for them. We only extend it for them so that they may increase in sin, and for them is a humiliating punishment.

But if you want to replace one wife with another and you have given one of them a great amount [in gifts], do not take [back] from it anything. Would you take it in injustice and manifest sin?

Indeed, Allah does not forgive association with Him, but He forgives what is less than that for whom He wills. And he who associates others with Allah has certainly fabricated a tremendous sin.

Look how they invent about Allah untruth, and sufficient is that as a manifest sin.

And whoever commits a sin only earns it against himself. And Allah is ever Knowing and Wise.

But whoever earns an offense or a sin and then blames it on an innocent [person] has taken upon himself a slander and manifest sin.

O you who have believed, do not violate the rites of Allah or [the sanctity of] the sacred month or [neglect the marking of] the sacrificial animals and garlanding [them] or [violate the safety of] those coming to the Sacred House seeking bounty from their Lord and [His] approval. But when you come out of ihram, then [you may] hunt. And do not let the hatred of a people for having obstructed you from al-Masjid al-Haram lead you to transgress. And cooperate in righteousness and piety, but do not cooperate in sin and aggression. And fear Allah; indeed, Allah is severe in penalty.

Prohibited to you are dead animals, blood, the flesh of swine, and that which has been dedicated to other than Allah, and [those animals] killed by strangling or by a violent blow or by a head-long fall or by the goring of horns, and those from which a wild animal has eaten, except what you [are able to] slaughter [before its death], and those which are sacrificed on stone altars, and [prohibited is] that you seek decision through divining arrows. That is grave disobedience. This day those who disbelieve have despaired of [defeating] your religion; so fear them not, but fear Me. This day I have perfected for you your religion and completed My favor upon you and have approved for you Islam as religion. But whoever is forced by severe hunger with no inclination to sin - then indeed, Allah is Forgiving and Merciful.

Indeed I want you to obtain [thereby] my sin and your sin so you will be among the companions of the Fire. And that is the recompense of wrongdoers."

And you see many of them hastening into sin and aggression and the devouring of [what is] unlawful. How wretched is what they have been doing.

Why do the rabbis and religious scholars not forbid them from saying what is sinful and devouring what is unlawful? How wretched is what they have been practicing.

O you who have believed, testimony [should be taken] among you when death approaches one of you at the time of bequest - [that of] two just men from among you or two others from outside if you are traveling through the land and the disaster of death should strike you. Detain them after the prayer and let them both swear by Allah if you doubt [their testimony, saying], "We will not exchange our oath for a price, even if he should be a near relative, and we will not withhold the testimony of Allah. Indeed, we would then be of the sinful."

But if it is found that those two were guilty of perjury, let two others stand in their place [who are] foremost [in claim] from those who have a lawful right. And let them swear by Allah, "Our testimony is truer than their testimony, and we have not transgressed. Indeed, we would then be of the wrongdoers."

And leave what is apparent of sin and what is concealed thereof. Indeed, those who earn [blame for] sin will be recompensed for that which they used to commit.

Say, "My Lord has only forbidden immoralities - what is apparent of them and what is concealed - and sin, and oppression without right, and that you associate with Allah that for which He has not sent down authority, and that you say about Allah that which you do not know."

Indeed, those who came with falsehood are a group among you. Do not think it bad for you; rather it is good for you. For every person among them is what [punishment] he has earned from the sin, and he who took upon himself the greater portion thereof - for him is a great punishment.

And those who harm believing men and believing women for [something] other than what they have earned have certainly born upon themselves a slander and manifest sin.

And those who avoid the major sins and immoralities, and when they are angry, they forgive,

O you who have believed, avoid much [negative] assumption. Indeed, some assumption is sin. And do not spy or backbite each other. Would one of you like to eat the flesh of his brother when dead? You would detest it. And fear Allah; indeed, Allah is Accepting of repentance and Merciful.

Those who avoid the major sins and immoralities, only [committing] slight ones. Indeed, your Lord is vast in forgiveness. He was most knowing of you when He produced you from the earth and when you were fetuses in the wombs of your mothers. So do not claim yourselves to be pure; He is most knowing of who fears Him.

Have you not considered those who were forbidden from private conversation, then they return to that which they were forbidden and converse among themselves about sin and aggression and disobedience to the Messenger? And when they come to you, they greet you with that [word] by which Allah does not greet you and say among themselves, "Why does Allah not punish us for what we say?" Sufficient for them is Hell, which they will [enter to] burn, and wretched is the destination.