adjective

feeling uncertain about something.

he looked doubtful, but gave a nod

irresolute,hesitant,tentative,vacillating,dithering,wavering,teetering,fluctuating,faltering,ambivalent,divided,in doubt,unsure,uncertain,in two minds,shilly-shallying,undecided,indefinite,unresolved,in a quandary/dilemma,undetermined,iffy,blowing hot and cold,sitting on the fence