The most common and most likely answer to this crossword clue is the 6 letter word BRAILS
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Buddy explains!

The straight part
We know that "Feathers of hawk" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case feathers of hawk = brails.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 BRAILS mean?
BRAILS noun- A small rope used to truss up sails.
- A thong of soft leather to bind up a hawk's wing.
- A stock at each end of a seine to keep it stretched.
- (in the plural) The feathers around a hawk's rump.
- To reef, shorten or strike sail using brails.