OMINOUSLY
ominously
(adverb) in an ominous manner; “the sun darkened ominously”
Source: WordNet® 3.1
Etymology
Adverb
ominously (comparative more ominously, superlative most ominously)
in an ominous manner; with sinister foreboding.
Source: Wiktionary
OMINOUS
Om"i*nous, a. Etym: [L. ominosus, fr. omen. See Omen.]
Definition: Of or pertaining to an omen or to omens; being or exhibiting an
omen; significant; portentous; -- formerly used both in a favorable
and unfavorable sense; now chiefly in the latter; foreboding or
foreshowing evil; inauspicious; as, an ominous dread.
He had a good ominous name to have made a peace. Bacon.
In the heathen worship of God, a sacrifice without a heart was
accounted ominous. South.
– Om"i*nous*ly, adv.
– Om"i*nous*ness, n.
Source: Webster’s Unabridged Dictionary 1913 Edition