The most common and most likely answer to this crossword clue is the 6 letter word YELPED
I've seen this crossword clue in The Daily Telegraph
Y
E
L
P
E
D
More clues leading to the result YELPED
Buddy explains!
The straight part
We know that "let out a scream" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case let out a scream = yelped.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 YELPED mean?
YELPED verb- To utter an abrupt, high-pitched noise.