The most common and most likely answer to this crossword clue is the 3 letter word MEW
M
E
W
More clues leading to the result MEW
Buddy explains!

The straight part
We know that "Gull/cry" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case gull/cry = mew.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 MEW mean?
MEW noun- A gull, seagull.
- A prison, or other place of confinement.
- A hiding place; a secret store or den.
- A breeding-cage for birds.
- A cage for hawks, especially while moulting.
- (in the plural) A building or set of buildings where moulting birds are kept.
- To shut away, confine, lock up.
- (of a bird) To moult.
- (of a bird) To cause to moult.
- (of a deer) To shed antlers.
- The crying sound of a cat; a meow, especially of a kitten.
- The crying sound of a gull.
- An exclamation of disapproval; a boo.
- (of a cat, especially of a kitten) To meow.
- A cat's (especially a kitten's) cry.
- A gull's cry.
- An exclamation of disapproval; boo.
- To flatten the tongue against the roof of the mouth for supposed health benefits.