dead spot
noun1
An area that has no radio (or wi-fi) reception.
2
Broadcasting, Cinematography, Film, Media, Television A part of a scene that has insufficient lighting.
3
Geography, Geology, Natural sciences, Seismology A location around an earthquake epicentre that is prone to earthquake.
4
Architecture The flaw of building that cannot be seen when collapsing because poor structure, built not according specified standards, or not earthquake-proof.