Direful, a.
Etymology: [Dire + -ful.]
Dire; dreadful; terrible; calamitous; woeful; as, a direful fiend; a direful day. -- Dire"ful*ly, adv. -- Dire"ful*ness, n.
Shades of meaning
Fernald has no entry of its own for direful; he lists it under awful.
He lists it without comment; the entries above explain its neighbors.