The most common and most likely answer to this crossword clue is the 13 letter word AMBIDEXTERITY
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M
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Buddy explains!

The straight part
We know that "making use of both Left and Right" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case making use of both left and right = ambidexterity.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 AMBIDEXTERITY mean?
AMBIDEXTERITY noun- The property of being equally skillful with each hand.
- Superior cleverness or adaptability.