Tremulous question about a victory (7)
I believe the answer is:
quavery
'tremulous' is the definition.
(thesaurus)
'question about a victory' is the wordplay.
'question' becomes 'query' (synonyms).
'about' is an insertion indicator.
'victory' becomes 'v'.
'a'+'v'='av'
'query' placed around 'av' is 'QUAVERY'.
(Other definitions for quavery that I've seen before include "trembling" , "Apt to tremble" .)