I wondered about feathers (9)
I believe the answer is:
eiderdown
'feathers' is the definition.
(eiderdown is a kind of feathers)
'i wondered about' is the wordplay.
'about' indicates anagramming the letters.
'i'+'wondered'='iwondered'
'iwondered' is an anagram of 'EIDERDOWN'.
(Other definitions for eiderdown that I've seen before include "What might keep one warm" , "cover when retired" , "Soft quilt filled with duck feathers" , "what keeps retired people warm" , "I wondered about this warm bed covering" .)