Problematic, Problematical, a.
Etymology: [L. problematicus, Gr. problématique.]
Having the nature of a problem; not shown in fact; questionable; uncertain; unsettled; doubtful. -- Prob`lem*at"ic*al*ly, adv. Diligent inquiries into remote and problematical guilt leave a gate wide open to . . . informers. Swift.
Shades of meaning
Fernald lists problematical only as an antonym, under imminent.
He lists it without comment; the entries above explain its neighbors.
Synonyms
none given