Hesitant (6)
'hesitant' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for unsure that I've seen before include "Lacking confidence" , "Far from certain" , "Not certain, somewhat confused" , "Not certain or confident" , "Not certain, undecided" .)
(Other definitions for tentative that I've seen before include "Conjectural" , "Experimental" , "Diffident" , "Not sure" , "Attentive in hesitant manner" .)
'hesitant' is the definition.
(thesaurus)
This is the entire clue.
(Other definitions for undecided that I've seen before include "Irresolute" , "Not yet having made a commitment" , "With mind not yet made up" , "Still up in the air?" , "Not settled" .)