/ Dictionary / Index A alto horn: Meaning and Definition of Find definitions for: al'to horn' Pronunciation: [key] althorn. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. altogether altoist Related Content Daily Word Quiz: entomology Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language