Part of speech: Adjective (satellite)
open to doubt or suspicion
Example: the candidate's doubtful past; he has a dubious record indeed; what one found uncertain the other found dubious or downright false; it was more than dubitable whether the friend was as influential as she thought"- Karen Horney
The word "dubitable" comes from Latin dubitabilis.
Legal and medical professions still use Latin phrases because of its precision and historical authority.