that is beheaded, break down, break (cut off, strike off) neck

Concise Bible Dictionary:

This was not a form of capital punishment in the Old Testament. Ishbosheth was beheaded by his murderers that his head might be carried to David (2 Sam. 4:7-87For when they came into the house, he lay on his bed in his bedchamber, and they smote him, and slew him, and beheaded him, and took his head, and gat them away through the plain all night. 8And they brought the head of Ish-bosheth unto David to Hebron, and said to the king, Behold the head of Ish-bosheth the son of Saul thine enemy, which sought thy life; and the Lord hath avenged my lord the king this day of Saul, and of his seed. (2 Samuel 4:7‑8)); as Goliath’s head had been carried to Saul. In the New Testament John the Baptist was killed in the Roman manner of beheading with the sword (Matt. 14:1010And he sent, and beheaded John in the prison. (Matthew 14:10); Mark 6:16, 2716But when Herod heard thereof, he said, It is John, whom I beheaded: he is risen from the dead. (Mark 6:16)
27And immediately the king sent an executioner, and commanded his head to be brought: and he went and beheaded him in the prison, (Mark 6:27)
; Luke 9:99And Herod said, John have I beheaded: but who is this, of whom I hear such things? And he desired to see him. (Luke 9:9)). In Revelation 20:44And I saw thrones, and they sat upon them, and judgment was given unto them: and I saw the souls of them that were beheaded for the witness of Jesus, and for the word of God, and which had not worshipped the beast, neither his image, neither had received his mark upon their foreheads, or in their hands; and they lived and reigned with Christ a thousand years. (Revelation 20:4), those “beheaded” for the witness of Jesus, may be killed in other ways, for the word πελεκίζω signifies “to cut with an ax,”‘ having no particular reference to the head.

Strong’s Dictionary of Hebrew Words:

a primitive root (identical with 6201 through the idea of sloping); properly, to bend downward; but used only as a denominative from 6203, to break the neck; hence (figuratively) to destroy
KJV Usage:
that is beheaded, break down, break (cut off, strike off) neck