Seismograms

Part of speech: noun

Definitions

1. A written or printed record produced by a seismograph showing the ground movements caused by earthquakes or other tremors
2. The graphic trace made by an instrument that detects vibrations in the earth, typically recording the strength and timing of quakes
3. A chart or line record of ground motion captured by a seismic recording device during an earthquake or blast

Etymology: The instrument behind the word is younger than many readers would guess: a seismogram is a record drawn by a seismograph, and the first half of the name comes from the Greek "seismós", meaning "earthquake" or "shaking", itself from "seíein", "to shake". The second half, "-gram", comes from the Greek "gramma", meaning "something written" or "letter", so the whole word literally means something like "earthquake writing." The "seismo-" element was used in English as a combining form, and the word was built from it in the same way modern scientific terms are assembled from classical pieces. The plural "seismograms" is simply the form used when more than one such record is meant, and it follows the regular English pattern of adding "-s" to the noun. Its origin is the same as for the singular.