manslayer

Concise Bible Dictionary:

ἀνθρωποκτόνος. (from ἄνθρωππς,man,' and κτείνω,to slay' agrees more with our word ‘man-slayer,' and is applied when murder may not have been committed. "Whosoever hateth his brother is a murderer: and ye know that no murderer hath eternal life abiding in him." 1 John 3:1515Whosoever hateth his brother is a murderer: and ye know that no murderer hath eternal life abiding in him. (1 John 3:15). The devil "was a murderer [mansleer, Wickliffe] from the beginning." John 8:4444Ye are of your father the devil, and the lusts of your father ye will do. He was a murderer from the beginning, and abode not in the truth, because there is no truth in him. When he speaketh a lie, he speaketh of his own: for he is a liar, and the father of it. (John 8:44). This word serves to bring into contrast the slaying of MAN, and eternal life for man through our Lord Jesus Christ.
σικάιος (the Latin sicarius) is so called from sica, a short dagger or poniard. There was a secret society called Sicarii, the members of which carried daggers under their garments, and killed any who opposed them. Perhaps ‘assassin' is the best equivalent. It occurs only in Acts 21:3838Art not thou that Egyptian, which before these days madest an uproar, and leddest out into the wilderness four thousand men that were murderers? (Acts 21:38).

Strong’s Dictionary of Greek Words:

Greek:
ἀνδροφόνος
Transliteration:
androphonos
Phonic:
an-drof-on’-os
Meaning:
from 435 and 5408; a murderer
KJV Usage:
manslayer