shadow

¹shad·ow

noun \ˈshad-(ˌ)ō, -ə(-w)\

Definition of SHADOW

1

a : partial darkness or obscurity within a part of space from which rays from a source of light are cut off by an interposed opaque body b : a dark outline or image on an X-ray photograph where the X-rays have been blocked by a radiopaque mass (as a tumor)

2

: a colorless or scantily pigmented or stained body (as a degenerate cell or empty membrane) only faintly visible under the microscope