penumbrous

Partially shaded.

the penumbrous calm of the cathedral interior

Vague; ill-defined; unclear.

Yet such Commissions were awarded, and far more frequently than might be supposed in view of the infinitely wider gulf—both social and educational—which divided the eighteenth-century Officer from the rank and file, than the penumbrous border line which separates them today.

Everyone knows God in his penumbrous knowledge of common esse.