The most common and most likely answer to this crossword clue is the 7 letter word PATENTS
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Buddy explains!

The straight part
We know that "legal protection" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case legal protection = patents.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 PATENTS mean?
PATENTS noun- A declaration issued by a government agency declaring someone the inventor of a new invention and having the privilege of stopping others from making, using or selling the claimed invention; a letter patent.
- A specific grant of ownership of a piece of property; a land patent.
- License; formal permission.
- Patent leather: a varnished, high-gloss leather typically used for shoes and accessories.
- To successfully register an invention with a government agency; to secure a letter patent.