SUPERCILIOUSLY
sneeringly, superciliously, snidely
(adverb) with a sneer; in an uncomplimentary sneering manner; “‘I don’t believe in these customs,’ he said sneeringly”
Source: WordNet® 3.1
Etymology
Adverb
superciliously (comparative more superciliously, superlative most superciliously)
In a supercilious manner.
Source: Wiktionary
SUPERCILIOUS
Su`per*cil"i*ous, a. Etym: [L. superciliosus, fr. supercilium an
eyebrow, pride; super over, + cilium an eyelid; probably akin to
celare to conceal. Cf. Conceal.]
Definition: Lofty with pride; haughty; dictatorial; overbearing; arrogant;
as, a supercilious officer; asupercilious air; supercilious behavior.
– Su`per*cil"i*ous*ly, adv.
– Su`per*cil"i*ous*ness, n.
Source: Webster’s Unabridged Dictionary 1913 Edition