/ Dictionary / Index L L wave: Meaning and Definition of Find definitions for: L wave Pronunciation: [key] an earthquake wave that travels around the earth's surface and is usually the third conspicuous wave to reach a seismograph. Also calledCf. P wave, S wave. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. LW lwei Related Content Daily Word Quiz: benevolent Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language