The most common and most likely answer to this crossword clue is the 6 letter word GRIPED
I've seen this crossword clue in The Times
G
R
I
P
E
D
More clues leading to the result GRIPED
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The straight part
We know that "released grouse" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case released grouse = griped.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 GRIPED mean?
GRIPED verb- To complain; to whine.
- To annoy or bother.
- To tend to come up into the wind, as a ship which, when sailing close-hauled, requires constant labour at the helm.
- To pinch; to distress. Specifically, to cause pinching and spasmodic pain to the bowels of, as by the effects of certain purgative or indigestible substances.
- To suffer griping pains.
- To make a grab (to, towards, at or upon something).
- To seize or grasp.