Where does the word “abhor” come from and What does it mean?

When the hair stands up from fright or dread, we have the literal meaning of abhor.

The Latin source of our verb was abhorreo, from ab, away from, and horreo, to stand on end, to bristle.

Thus the literal meaning was to shrink back from with horror, but, though the verb still expresses great repugnance, it no longer conveys the notion of shuddering dread or fear that its use indicated to the Romans.