Article gets through like a bird (5)
I believe the answer is:
avian
'like a bird' is the definition.
(I've seen this in another clue)
'article gets through' is the wordplay.
'article' becomes 'an' (indefinite article).
'gets' indicates putting letters inside (gets can mean captures or absorbs).
'through' becomes 'via' (via means going through).
'an' placed around 'via' is 'AVIAN'.
(Other definitions for avian that I've seen before include "Resembling a bird" , "Lizard with adhesive foot-pads" , "To do with birds - like a dangerous flu" , "Relating to birds" , "Regarding birds" .)