The exact date of his advent to that place seems to be unascertainable, but it was more than fifty years ago.
There was first the Procession of the Maestranza, of unascertainable antiquity.
The back yard is unfenced, and extends to the sky-line and an unascertainable bit beyond.
Antonyms: unknowable, unascertainable, incognoscible, unrecognizable.
The German losses were, of course, unascertainable, but they were undoubtedly very much higher than ours.
The composition of the earliest inks has not yet been obtained and, likely, is unascertainable.
During the seventh century many sanguinary battles were fought, the sites of which are now unascertainable.
Its exact amount is unascertainable, for neither Government kept adequate statistics before 1820.
early 15c., "to inform, to give assurance," from Anglo-French acerteiner, Old French acertener "to assure, certify" (13c.), from a "to" (see ad-) + certain "certain" (see certain). Modern meaning of "find out for sure by experiment or investigation" is first attested 1794. Related: Ascertained; ascertaining.