DREADFULLY
dreadfully, awfully, horribly
(adverb) of a dreadful kind; “there was a dreadfully bloody accident on the road this morning”
dismally, dreadfully
(adverb) in a dreadful manner; “as he looks at the mess he has left behind he must wonder how the Brits so often managed to succeed in the kind of situation where he has so dismally failed”
Source: WordNet® 3.1
Etymology
Adverb
dreadfully (comparative more dreadfully, superlative most dreadfully)
In a dreadful manner.
(dated) Exceptionally, eminently, very much.
Source: Wiktionary
Dread"ful*ly, adv.
Definition: In a dreadful manner; terribly. Dryden.
DREADFUL
Dread"ful, a.
1. Full of dread or terror; fearful. [Obs.] "With dreadful heart."
Chaucer.
2. Inspiring dread; impressing great fear; fearful; terrible; as, a
dreadful storm. " Dreadful gloom." Milton.
For all things are less dreadful than they seem. Wordsworth.
3. Inspiring awe or reverence; awful. [Obs.] "God's dreadful law."
Shak.
Syn.
– Fearful; frightful; terrific; terrible; horrible; horrid;
formidable; tremendous; awful; venerable. See Frightful.
Source: Webster’s Unabridged Dictionary 1913 Edition