- remarkable; astonishing: They're raising a hellacious amount of money in taxes.
- formidably difficult: We had a hellacious time getting here in the blizzard.
Origin of hellacious
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018
- remarkable; horrifying
- wonderful; excellent
C20: from hell + -acious as in audacious
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Word Origin and History for hellacious
Online Etymology Dictionary, © 2010 Douglas Harper