"Doubtful" is a word in ENGLISH

Characterized by ambiguity; dubious; as, a doubtful
expression; a doubtful phrase.

Not settled in opinion; undetermined; wavering;
hesitating in belief; also used, metaphorically, of the body when its
action is affected by such a state of mind; as, we are doubtful of a
fact, or of the propriety of a measure.

Admitting of doubt; not obvious, clear, or certain;
questionable; not decided; not easy to be defined, classed, or named;
as, a doubtful case, hue, claim, title, species, and the like.

Fearful; apprehensive; suspicious.

Of uncertain issue or event.