What is the definition of murder in Islam? Is pressing someone's neck in anger for one or two second but not taking his life and causing no damage to him is also murder? what's ruling on it?

All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His slave and Messenger.

Murder in Islam is to do what would cause the death of a person – namely that which causes the soul leave the body. There is no doubt that it is forbidden to abuse a Muslim through suffocation or other means. If pressing someone's neck does not result in death, then this is not murder at all, and no one would call that murder.

If the person whose neck was pressed does not forgive the transgressor, then the transgressor is to be punished by the authorities (through Ta'zeer, or discretionary punishment), according to the majority of scholars. For more benefit, please refer to Fatwa 184083.

Shaykh Ibn Taymiyyah preferred the opinion that the victim would be enabled to do the same thing to the person who violated him; this is because the Sunnah of the Prophet and the Rightly-Guided Caliphs, may Allaah be pleased with them, is Qisaas (legal retribution) in this regard.

But if someone kills someone else by pressing his neck, then this entails Qisaas according to the majority of scholars. For more benefit, please refer to Fatwa 86255.

Allaah Knows best.