c. 1300, agheful, aueful, "worthy of respect or fear, striking with awe; causing dread," from aghe, an earlier form of awe (n.), + -ful. The Old English word was egefull. The weakened sense of "very bad" is by 1809; the weakened sense of "excessively; very great" is by 1818. It formerly also was occasionally used in a sense of "profoundly reverential, full of awe" (1590s).
updated on November 30, 2022