Dreaded describes something that makes you afraid or anxious — the thing you would rather not face. Though actually, in everyday English it is very often a small joke: “the dreaded Monday morning,” “the dreaded phone call from Mum.” The speaker is not truly terrified; they are making a warm fuss about something awkward or annoying. Without that playful tone it can still be serious: a dreaded disease, a dreaded exam. It is the adjective from dread, to feel great fear.