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Meaning of hellacious

hel•la•cious

Pronunciation: (he-lā'shus), [key]
— adj. Slang.
  1. remarkable; astonishing: They're raising a hellacious amount of money in taxes.
  2. formidably difficult: We had a hellacious time getting here in the blizzard.
Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease.