See Definition for phoneus { [G5406]}
See Definition for anthropoktonos { [G443]}
See Definition for sikarios { [G4607]}
Both in derivation and usage, phoneus and anthropoktonos are
distinguished from each other just as the English murderer from
manslayer or homicide.
sikarios, used only in Ac 21:38, is the Latin sicarius,
and means an assassin, usually hired for the work, who furtively
stabbed his enemy with a short sword, the Latin sica. phoneus
is a generic word and may denote a murderer of any kind, sikarios
being one of the specific varieties which it includes.