- In radio communications, a region where reception is significantly weaker, due to obstructions. Also called blind zone (1).
- In radars, an area with no echoes, due to obstructions. Also called blind zone (2).
- In radio communications, an area within the normal range of a transmitter, where radio reception is poor or non-existent, due to large objects in the vicinity of the receiver.
- synonymshadow area
- synonymshadow zone