P wave


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.

Compare L wave, S wave.

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. 2019

Word Origin and History for p wave

1908 in geology, the p representing primary (adj.).

Online Etymology Dictionary, © 2010 Douglas Harper

p wave in Medicine

P wave


A deflection in an electrocardiogram indicating depolarization of the atria.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

p wave in Science

P wave

See primary wave.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.