Hostility; hatred.

And the LORD God said unto the serpent, Because thou hast done this, thou art cursed above all cattle, and above every beast of the field; upon thy belly shalt thou go, and dust shalt thou eat all the days of thy life: and I will put ENMITY between thee and the woman, and between thy seed and her seed; it shall bruise thy head, and thou shalt bruise his heel. ( Genesis 3:14-15 )