Strong’s Greek
G3990 — pelekizo
The entry below is Strong’s own definition (1890, public domain), and every verse where the word occurs.
πελεκίζω
pelekizo — pronounced pel-ek-id'-zo
from a derivative of 4141 (meaning an axe); to chop off (the head), i.e. truncate:--behead. see GREEK for 4141
1 occurrence in the KJV.
Revelation 20:4
And 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.