The most common and most likely answer to this crossword clue is the 8 letter word SQUAWKED
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More clues leading to the result SQUAWKED
Buddy explains!

The straight part
We know that "Screeched" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case screeched = squawked.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 SQUAWKED mean?
SQUAWKED verb- To make a squawking noise; to yell, scream, or call out shrilly.
- To speak out; to protest.
- To report an infraction; to rat on or tattle; to disclose a secret.
- To produce a warning message, indicating a possible error.
- To set or transmit a four-digit transponder code. (Normally followed by the specific code in question.)
- To back out in a mean way.