Artwork features headless parrot in cage (7)

I believe the answer is:

collage

I'm a little stuck... Click here to teach me more about this clue!

'artwork' is the definition.
(I've seen this before)

I cannot understand how the remainder of the clue works.

(Other definitions for collage that I've seen before include "Artwork formed from scraps of paper, photos etc" , "work of art" , "work being stuck" , "Art form using glued pieces" , "Art form using pieces stuck on" .)

I've seen this clue in The Sun.

Want a hint initially instead of a full solution? Install my app