I-adjective (keiyoushi)
uneasy; unsure; anxious
あの人の言うことはどうも心もとないわね。I cannot place confidence in his words. unreliable; untrustworthy; erratic; undependable
nervous; impatient; irritated from anxiety
Archaic
unclear; indistinct; vague
Archaic
Also written 心許ない【こころもとない】、心許無い【こころもとない】