phonos

This is the noun for murder, the deed itself rather than the person who does it or the moment of doing it. Greek has a matching set of words: the verb for committing it (φονεύω) and the word for the man who has (φονεύς). This one is what you reach for when you want to name the crime, which is why it shows up both on charge sheets and in lists of sins.

Across its ten appearances in the New Testament it covers a small but real range:

• a single killing that a named man was jailed for, as with the prisoner released instead of Jesus
• murder listed among the evils that come out of a corrupt human heart
• the deadly violence a man is set on before he has shed any blood, as with Saul on the road to Damascus
• the violent death inflicted on someone, where no crime is being charged at all

That last use is the one an English reader is most likely to miss. Hebrews describes faithful people who died by the sword, and the word there simply names the killing they suffered. It makes no accusation against them, because any accusation would fall on the ones holding the weapon. Greek keeps a separate noun for the butchering of animals or victims (σφαγή), so even when this word names a death rather than a crime, its focus stays on a person violently killed.

What the word does carry, which the ordinary Greek verb for killing (ἀποκτείνω) does not, is a sense of wrong. Soldiers kill, courts execute, and God puts to death, all with that broader verb. This word points at the wrong in taking a life, which is why Paul can drop it into the middle of a list of things that shut people out of God's kingdom.