The most common and most likely answer to this crossword clue is the 1 plus 1 plus 4 letter word I Q TEST
I
Q
T
E
S
T
More clues leading to the result I Q TEST
Buddy explains!
The straight part
We know that "To be exceptional, one has to have a score of at least 120" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case to be exceptional, one has to have a score of at least 120 = i q test.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.