Definitions

1. noun

The innermost and darkest part of a shadow, where the light source is completely blocked from view, and where the light intensity is zero.

“The umbra of the tree fell across the grass, creating a dark patch.”

2. noun

A region within the shadow of a celestial body, such as the Earth, where the sunlight is completely blocked and where the light intensity is zero.

“The umbra of the Earth during a lunar eclipse is where the Moon passes through and appears dark.”

3. noun

A region of partial shade, especially in a garden or landscape.

“The garden path received dappled sunlight, creating an umbra of coolness amidst the warm summer air.”