dubious

Concise Oxford English Dictionary © 2008 Oxford University Press:
dubious /ˈdjuːbɪəs/

▶adjective

• 1 hesitating or doubtful.

• 2 morally suspect.

  ■ of questionable value or reliability.

– derivatives
dubiously adverb,
dubiousness noun.

– origin C16: from L. dubiosus, from dubium ‘a doubt’, neut. of dubius ‘doubtful’.