S0221200 (sīz′mə-grăf′)n. An instrument for automatically detecting and recording the intensity, direction, and duration of a movement of the ground, especially of an earthquake.seis·mog′ra·pher(sīz-mŏg′rə-fər) n.seis′mo·graph′ic(-grăf′ĭk), seis′mo·graph′i·cal(-ĭ-kəl) adj.seis·mog′ra·phy n.EncyclopediaSeeseismograph