Pre*pos"ter*ous (?), a.[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.

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!

Syn. -- Absurd; perverted; wrong; irrational; foolish; monstrous. See Absurd.

-- Pre*pos"ter*ous*ly, adv. - Pre*pos"ter*ous*ness, n.