* φόνος (phónos): This word refers to murder or killing itself, not necessarily the person who commits it. It's closer to "murder" or "killing" than "killer."
* δολοφόνος (dolophónos): This is a more direct translation of "killer," specifically referring to someone who commits murder. It implies a deliberate and often malicious act.
* ανθρωποκτόνος (anthrōpoktonos): This literally means "man-slayer" or "murderer" and is a more formal and emphatic term.
The best word to use would depend on the specific situation. For example, in a news report, δολοφόνος (dolophónos) would likely be used. If discussing a mythological figure who committed a killing, ανθρωποκτόνος (anthrōpoktonos) might be more appropriate. If referring to the act of killing in a more abstract sense, φόνος (phónos) might be the best choice.