Earthshock n. : An earthquake.

Example:


Taxonomy
Doctor, Earthshock, Cybermen, Adric, freighter, Doctor Who, lock, Nyssa, Earth, TARDIS crew, Cyber Leader, Broadcast, DVD releases, androids, clip, crew members, free encyclopedia, Matthew Waterhouse.

Defination from the web:
Earthshock is a serial in the British science fiction television series Doctor Who, which was first broadcast in four twice-weekly parts from March 8 to March 16, 1982. ... Before the title was changed to Earthshock, Nathan-Turner was adamant about keeping the return of the Cybermen a secret. ...