The most common and most likely answer to this crossword clue is the 8 letter word ENDORSES
I've seen this crossword clue in The Daily Telegraph
E
N
D
O
R
S
E
S
Buddy explains!
The straight part
We know that "Sanctions" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case sanctions = endorses.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 ENDORSES mean?
ENDORSES noun- A diminutive of the pale, usually appearing in pairs on either side of a pale.
- To support, to back, to give one's approval to, especially officially or by signature.
- To write one's signature on the back of a cheque, or other negotiable instrument, when transferring it to a third party, or cashing it.
- To give an endorsement.