The most common and most likely answer to this crossword clue is the 9 letter word SANCTIONS
I've seen this crossword clue in The Daily Telegraph
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Buddy explains!
The straight part
We know that "Gives the green light to/restrictions" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case gives the green light to/restrictions = sanctions.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 SANCTIONS mean?
SANCTIONS noun- An approval, by an authority, generally one that makes something valid.
- A penalty, punishment, or some coercive measure, intended to ensure compliance; especially one adopted by several nations, or by an international body.
- A law, treaty, or contract, or a clause within a law, treaty, or contract, specifying any of the above.
- To ratify; to make valid.
- To give official authorization or approval to; to countenance.
- To penalize (a State etc.) with sanctions.