/ Dictionary / Index E extn.: Meaning and Definition of Find definitions for: extn. Pronunciation: [key] extension. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. extirpate extol Related Content Daily Word Quiz: arboreal Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language