/ Dictionary / Index L Lassen Volcanic National Park: Meaning and Definition of Find definitions for: Las'sen Volcan'ic Na'tional Park' Pronunciation: [key] a national park in N California, in the S Cascade Range, including Lassen Peak. 163 sq. mi. (422 sq. km). Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. Lassen Peak lassie Related Content Daily Word Quiz: mamba Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language