The most common and most likely answer to this crossword clue is the 7 letter word LOOSING
I've seen this crossword clue in The Guardian
L
O
O
S
I
N
G
Buddy explains!

The straight part
We know that "Releasing" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case releasing = loosing.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 LOOSING mean?
LOOSING verb- To let loose, to free from restraints.
- To unfasten, to loosen.
- To make less tight, to loosen.
- Of a grip or hold, to let go.
- To shoot (an arrow)
- To set sail.
- To solve; to interpret.