Anchoring, gripping claws finally (8)
I believe the answer is:
roosting
'anchoring' is the definition.
(both can mean settling somewhere)
I cannot understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for roosting that I've seen before include "Of birds, settling for sleep" , "Trying to sleep" , "Perching, as fowl do" , "in place of sleep?" , "Sitting like a bird" .)