PENUMBRA

O struggling with the darkness all the night
And visited all night by troops of stars

SAMUEL TAYLOR COLERIDGE 1809

PENUMBRA: An Imperfect Shadow

The partial shaded region around the shadow of an opaque body;
the partial shadow as distinguished from the total shadow or umbra.

Oxford English Dictionary 1971

The shadow consists of two parts; the umbra or total shadow, a cone
into which no direct sunlight penetrates, and the penumbra or half
shadow which is reached by light from only a part of the sun’s disk.

Encyclopaedia Britannica 1957

SHADOW LEND
SHADOW LEND

What is your substance, whereof are you made,
That millions of strange shadows on you tend?
Since every one hath, every one, one shade,
And you, but one, can every Shadow Lend.

WILLIAM SHAKESPEARE 1609