dreadful

/ˈdrɛdfəl/
adjective
  1. Causing great fear, terror, or unhappiness; extremely bad or unpleasant.
    • The movie was so dreadful that we left after twenty minutes.
    • She had a dreadful headache and couldn't concentrate on her work.
    • The storm caused dreadful damage to the coastal town.
  2. Used to emphasize how bad something is; extreme in a negative way.
    • The traffic this morning was dreadful; it took me two hours to get to work.
    • I made a dreadful mistake by sending that email to the wrong person.
    • He has a dreadful habit of interrupting people when they speak.