horrendous
1. [ adjective ] causing fear or dread or terror
Synonyms: terrible frightening dreadful awful fearful fearsome dreaded dread horrific direful dire
Examples:

"the awful war" "an awful risk" "dire news" "a career or vengeance so direful that London was shocked" "the dread presence of the headmaster" "a dreaded disease" "a dreadful storm" "a fearful howling"

Related terms: alarming
Similar spelling:   horned_pout
  horned_owl
  horned_asp
  hour_hand