1. An imperfect shadow; imperfect shadow between the total shadow and the full light; where the light and the shade are blended.

Nuttall's Standard dictionary of the English language By Nuttall, P.Austin

• oenumbra,
• lenumbra,
• -enumbra,
• 0enumbra,
• pwnumbra,
• pemnumbra,
• penumbera,
• penumbrea,
• penumra,
• pennumbra,
• penumbrra,
• penembra,
• penumbri,
• pe numbra,
• pentmeran,
• pennumbrala,
• pemumbral,
• penembral,
• penumbrel,
• prelumbr

• penumbral.

The adjective form of "penumbra" is "penumbral".