To be undecided about; to lack confidence in; to disbelieve, to question.
Disbelief or uncertainty (about something); (countable) a particular instance of such disbelief or uncertainty.
To have no confidence in (something or someone).
To be suspicious.
To be wary, suspicious or doubtful of (something or someone).
To suspect, to imagine or suppose (something) to be the case.
Lack of trust or confidence; distrust, untrust.