The Saint may be undecided (8)
I believe the answer is:
hesitant
'undecided' is the definition.
(I've seen this in another clue)
'the saint may be' is the wordplay.
'may be' indicates an anagram.
'the'+'saint'='thesaint'
'thesaint' anagrammed gives 'HESITANT'.
(Other definitions for hesitant that I've seen before include "Tentative" , "Indecisive" , "The Saint? (anag)" , "Demurring" , "Slow to speak or act" .)