Spy that's centre stage, strangely (6,5)
I believe the answer is:
secret agent
'spy' is the definition.
(thesaurus)
'centre stage strangely' is the wordplay.
'strangely' indicates anagramming the letters.
'centre'+'stage'='centrestage'
'centrestage' is an anagram of 'SECRET AGENT'.
'that's' is the link.
(Other definitions for secret agent that I've seen before include "007 - centre stage (anag)" , "Spy" , "Conrad character" .)