/ Dictionary / Index H hellacious: Meaning and Definition of Find definitions for: hel•la•cious Pronunciation: (he-lā'shus), [key] — adj. Slang. remarkable; astonishing: They're raising a hellacious amount of money in taxes. formidably difficult: We had a hellacious time getting here in the blizzard. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. hell Helladic Related Content Daily Word Quiz: fresco Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language