English
hellacious
Unclear origins; perhaps from hell + -acious
Formed from hell + -acious
Proto-Germanic *haljō ‘hell’
Proto-West Germanic *hallju ‘the netherworld’
Old English hel
Middle English hel
English hell
Today it means
adj horrible, awful, hellish, agonizing, difficult.
Language periods are conventional ranges, not dates for this word.
Etymograph / hellacious