Killing Intent

is simply the user exuding pure killing intention, and having it affect their opponent, themselves, and others around them, up to the point of paralysing them with fear. When the killing intent is particularly strong, it can even give the victim visions of their own gruesome death. This can cause killing intent to be confused with a genjutsu, despite it not being a jutsu at all. Amado has weaponized killing intent through scientific ninja tools to a great degree with Daemon, the mere thought of killing him being enough to trigger the reflection of an attack against an assailant.

Trivia

 * can also be translated to "thirst for blood".
 * In Naruto the Movie: Blood Prison, Satori is capable of reading killing intent and fear of its opponents, allowing it to instinctively dodge such attacks.