Artwork, huge, lacking centrepiece: pass over that (7)
I believe the answer is:
collage
'artwork' is the definition.
(I've seen this before)
'huge lacking centrepiece pass over that' is the wordplay.
'huge' becomes 'large' ('large' can be similar in meaning to 'huge').
'lacking centrepiece' says to hollow out the word (remove centre letters).
'pass' becomes 'col' (col is a kind of pass**).
'over that' says to put letters next to each other.
'large' with its middle taken out is 'lage'.
'lage' put after 'col' is 'COLLAGE'.
(Other definitions for collage that I've seen before include "Artwork formed from scraps of paper, photos etc" , "Style of artwork" , "Art form using pieces stuck on" , "work of art" , "Assembled-fragments art" .)