Huge performance trick (8)
I believe the answer is:
gigantic
'huge' is the definition.
(synonyms)
'performance trick' is the wordplay.
'performance' becomes 'gig' (a gig is a musical concert).
'trick' becomes 'antic' (synonyms).
'gig'+'antic'='GIGANTIC'
(Other definitions for gigantic that I've seen before include "Great big" , "Extremely large" , "Titanic" , "Huge, enormous" , "Exceedingly large" .)