英语词源字典 - 在线词源网站

awfully (adv.)[awfully 词源字典]: c. 1300, "so as to inspire reverence," from awful + -ly (2). Meaning "dreadfully, so as to strike one with awe" is recorded from late 14c. As a simple intensifier, "very, exceedingly," is attested from c. 1830.[awfully etymology, awfully origin, 英语词源]
dreadful (adj.): early 13c., "full of dread," from dread (n.) + -ful. Meaning "causing dread" is from mid-13c.; weakened sense of "very bad" is from c. 1700. Related: Dreadfully.
terribly (adv.): "dreadfully, so as to cause terror, in a horrible manner," mid-15c., from terrible + -ly (2). In the sense of "extremely" it is first recorded 1833; in the sense of "extremely badly" it dates from 1930.