/ Dictionary / Index H hor. un. spatio: Meaning and Definition of Find definitions for: hor. un. spatio Pronunciation: [key] (in prescriptions) at the end of one hour. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. hortus siccus Horus Related Content Daily Word Quiz: immense Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language