- a longitudinal earthquake wave that travels through the interior of the earth and is usually the first conspicuous wave to be recorded by a seismograph.
Origin of P wave
First recorded in 1935–40
Also called primary wave.
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
Word Origin and History for p wave
1908 in geology, the p representing primary (adj.).
Online Etymology Dictionary, © 2010 Douglas Harper
- A deflection in an electrocardiogram indicating depolarization of the atria.
- See primary wave.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.