Boyd’s Bible Dictionary:
The involuntary manslayer found escape in a city of refuge
(Num. 35:22-23; Deut. 19:5).
Concise Bible Dictionary:
The words φονεύς, ἀνθρωποκτόνος, and σικάριος are all translated ‘murderer.' φονεύω, the kindred verb to φονεύς (from φόνος, ‘murder') is employed in the LXX in the commandment "Thou shalt not kill," and is repeated in the N. T. This shows that it embraces ‘murder' in general, and those guilty of it are ‘murderers,' Matt. 22:7; 1 Pet. 4:15. Barabbas was a murderer, and the people of Israel were the murderers of Jesus. Acts 3:14; 7:52; 28:4.
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 3:15. The devil "was a murderer [mansleer, Wickliffe] from the beginning." 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 21:38.
Strong’s Dictionary of Greek Words:
Transliteration:
androphonos