D defs.my
Entry 1 sense Webster, 1913

Seismic

/sīz'-mĭk/ · Seis·mic · IPA /ˈsaɪzmɪk/
01 a. Of or pertaining to an earthquake; caused by an earthquake.
  1. 1.
    Of or pertaining to an earthquake; caused by an earthquake.
Phrases & compounds
Seismic vertical — the point upon the earth's surface vertically over the center of effort or focal point whence the earthquake's impulse proceeds, or the vertical line connecting these two points.