PREPOSTEROUSLY
laughably, ridiculously, ludicrously, preposterously
(adverb) so as to arouse or deserve laughter; “her income was laughably small, but she managed to live well”
Source: WordNet® 3.1
Etymology
Adverb
preposterously (comparative more preposterously, superlative most preposterously)
In a preposterous manner.
Source: Wiktionary
PREPOSTEROUS
Pre*pos"ter*ous a.Etym: [L. praeposterus; prae before + posterus
coming after, latter. See Posterior.]
1. Having that first which ought to be last; inverted in order.
[Obs.]
The method I take may be censured as preposterous, because I thus
treat last of the antediluvian earth, which was first in the order of
nature. Woodward.
2. Contrary to nature or reason; not adapted to the end; utterly and
glaringly foolish; unreasonably absurd; perverted. "Most preposterous
conclusions." Shak.
Preposterous ass, that never read so far! Shak.
Syn.
– Absurd; perverted; wrong; irrational; foolish; monstrous. See
Absurd.
– Pre*pos"ter*ous*ly, adv. -Pre*pos"ter*ous*ness, n.
Source: Webster’s Unabridged Dictionary 1913 Edition