Exaggerate deliveries going to art gallery (9)
I believe the answer is:
overstate
'exaggerate' is the definition.
(synonyms)
'deliveries going to art gallery' is the wordplay.
'deliveries' becomes 'overs' (cricket term).
'going to' says to put letters next to each other.
'art gallery' becomes 'tate' (I've seen this before).
'overs'+'tate'='OVERSTATE'
(Other definitions for overstate that I've seen before include "Exaggerate, go beyond bounds of truth" , "lay it on thick" , "Exaggerate, make too much of" .)