King James Bible Dictionary

EXECU'TION, noun Performance; the act of completing or accomplishing.

The excellence of the subject contributed much to the happiness of the execution

1. In law, the carrying into effect a sentence or judgment of court; the last act of the law in completing the process by which justice is to be done, by which the possession of land or debt, damages or cost, is obtained, or by which judicial punishment is inflicted.

2. The instrument, warrant or official order, by which an officer is empowered to carry a judgment into effect. An execution issues from the clerk of a court, and is levied by a sheriff, his deputy or a constable, on the estate, goods or body of the debtor.

3. The act of signing and sealing a legal instrument, or giving it the forms required to render it a valid act; as the execution of a deed.

4. The last act of the law in the punishment of criminals; capital punishment; death inflicted according to the forms of law.

5. Effect; something done or accomplished.

Every shot did execution

6. Destruction; slaughter.

It is used after do, to do execution; never after make.

7. Performance, as in music or other art.

(Mark 6:27). Instead of the Greek word, Mark here uses a Latin word, speculator, which literally means "a scout," "a spy," and at length came to denote one of the armed bodyguard of the emperor. Herod Antipas, in imitation of the emperor, had in attendance on him a company of speculatores. They were sometimes employed as executioners, but this was a mere accident of their office. (See MARK, GOSPEL ACCORDING TO.)

General references
Genesis 37:36; Proverbs 16:14; Jeremiah 39:9; Daniel 2:14; Matthew 14:10
Punishment

The post of executioner was one of high dignity. Potiphar was "captain of the executioners." (Genesis 37:36) see margin. That the "captain of the guard" himself occasionally performed the duty of an executioner appears from (1 Kings 2:25,34)

EXECU'TIONER, noun One who executes; one who carries into effect a judgment of death; one who inflicts a capital punishment in pursuance of a legal warrant. It is chiefly used in this sense.

1. He that kills; he that murders.

2. The instrument by which any thing is performed.