DOUBTFULLY
doubtfully, dubiously
(adverb) in a doubtful manner; “Gerald shook his head doubtfully”
Source: WordNet® 3.1
Etymology
Adverb
doubtfully (comparative more doubtfully, superlative most doubtfully)
In a doubtful manner, in context of doubt or ambiguity, questionably.
Source: Wiktionary
Doubt"ful*ly, adv.
Definition: In a doubtful manner.
Nor did the goddess doubtfully declare. Dryden.
DOUBTFUL
Doubt"ful, a.
1. Not settled in opinion; undetermined; wavering; hesitating in
belief; also used, metaphorically, of the body when its action is
affected by such a state of mind; as, we are doubtful of a fact, or
of the propriety of a measure.
Methinks I should know you, and know this man; Yet I am doubtful.
Shak.
With doubtful feet and wavering resolution. Milton.
2. Admitting of doubt; not obvious, clear, or certain; questionable;
not decided; not easy to be defined, classed, or named; as, a
doubtful case, hue, claim, title, species, and the like.
Beauty is but a vain and doubtful good. Shak.
Is it a great cruelty to expel from our abode the enemy of our peace,
or even the doubtful friend [i. e., one as to whose sincerity there
may be doubts] Bancroft.
3. Characterized by ambiguity; dubious; as, a doubtful expression; a
doubtful phrase.
4. Of uncertain issue or event.
We . . . have sustained one day in doubtful fight. Milton.
The strife between the two principles had been long, fierce, and
doubtful. Macaulay.
5. Fearful; apprehensive; suspicious. [Obs.]
I am doubtful that you have been conjunct And bosomed with her. Shak.
Syn.
– Wavering; vacillating; hesitating; undetermined; distrustful;
dubious; uncertain; equivocal; ambiguous; problematical;
questionable.
Source: Webster’s Unabridged Dictionary 1913 Edition