The bird did fly inside to get under cover (6)
I believe the answer is:
hidden
'under cover' is the definition.
(thesaurus)
'the bird did fly inside' is the wordplay.
'the bird' becomes 'hen' (hen is a kind of bird).
'fly' indicates anagramming the letters.
'inside' means one lot of letters goes inside another.
'did' anagrammed gives 'idd'.
'hen' placed around 'idd' is 'HIDDEN'.
'to get' acts as a link.
(Other definitions for hidden that I've seen before include "not obvious" , "behind closed doors" , "Deliberately placed out of sight and hard to find" , "Abstruse" , "Concealed, placed out of sight" .)