The most common and most likely answer to this crossword clue is the 9 letter word REPULSIVE
I've seen this crossword clue in The Guardian
R
E
P
U
L
S
I
V
E
More clues leading to the result REPULSIVE
- Terrible evil associated with super criminal
- Queen upped the beat, covering 6 – flipping gross!
- Note, drip’s captivated by heart- throb – that’s disgusting!
- Pure evil’s extraordinarily disgusting
- Super-vile, possibly
- Horrid, almost feverish throb with intravenous injection
- Rule VIPs broke getting drug being loathsome
- Flipping fantastic admitting large compiler’s ugly
- Provoking hatred, pure evil’s let loose
- Disgusting misuse of superlative – disheartened aspirant withdraws
Buddy explains!

The straight part
We know that "Terrible" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case terrible = repulsive.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does REPULSIVE mean?
REPULSIVE adjective- Tending to rouse aversion or to repulse
- Having the capacity to repel
- Cold, reserved, forbidding