The most common and most likely answer to this crossword clue is the 10 letter word CLEVERNESS
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More clues leading to the result CLEVERNESS
Buddy explains!

The straight part
We know that "genius" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case genius = cleverness.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 CLEVERNESS mean?
CLEVERNESS noun- The property of being clever.
- Something clever, or done cleverly.