As you might have notices when you were doing your dictionary research, the two can be used as synonyms, but horrible can also be used to mean unpleasant.

I had a horrible commute.

probably means the traffic was bad.

I had a horrific commute.

could mean there was a bad accident on the side of the road (or else I'm using a little hyperbole).

As you might have noticed when you were doing your dictionary research, the two can be used as synonyms, but horrible can also be used to mean unpleasant.

I had a horrible commute.

probably means the traffic was bad.

I had a horrific commute.

could mean there was a bad accident on the side of the road (or else I'm using a little hyperbole).