in-dŭbĭto, āvi, ātum, 1, v. n.,
to doubt of (poet.); with dat.: viribus tuis, Verg. A. 8, 404: tuis moribus, Stat. S. 3, 5, 110.
in-dubitō —, —, āre, to throw doubt upon, express distrust of: Viribus tuis, V. ...
An Elementary Latin Dictionary