/ˈsīzmik/
Relating to earthquakes or other vibrations of the earth and its crust.
"San Francisco will not withstand a seismic event."
Relating to or denoting geological surveying methods involving vibrations produced artificially by explosions.
Of enormous proportions or effect.
Mid 19th century: from Greek seismos ‘earthquake’ (from seien ‘to shake’) + -ic.