SHADOWING

To shade, cloud or darken.

"The artist chose to shadow this corner of the painting."

To block light or radio transmission from.

"Looks like that cloud's going to shadow us."

To secretly or discreetly track or follow another, to keep under surveillance.

The effect of being shadowed (in the sense of blocked), as from a light source or radio transmission.

The situation where an individual repeats speech immediately as they hear it (usually through earphones).

Secretly or discreetly tracking or following someone, keeping under surveillance.