/ Dictionary / Index P population explosion: Meaning and Definition of Find definitions for: popula'tion explo"sion Pronunciation: [key] the rapid increase in numbers of a particular species, esp. in the world's human population since the end of World War II, attributed to an accelerating birthrate, a decrease in infant mortality, and an increase in life expectancy. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. population population genetics Related Content Daily Word Quiz: careening Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language