Tumbler's performance involving wild boar (7)
I believe the answer is:
acrobat
'tumbler's' is the definition.
(synonyms)
'performance involving wild boar' is the wordplay.
'performance' becomes 'act' (act is a kind of performance).
'involving' is an insertion indicator.
'wild' indicates anagramming the letters.
'boar' anagrammed gives 'roba'.
'act' enclosing 'roba' is 'ACROBAT'.
(Other definitions for acrobat that I've seen before include "One appearing head over heels" , "Taco bar (anag.)" , "Performer of great agility and coordination" , "Rope-dancer" , "Agile entertainer" .)