1. Literally, having that first which ought to be last; inverted in order.
The method I take may be censured as preposterous, because I treat last of the antediluvian earth, which was first in the order of nature.
2. Perverted; wrong; absurd; contrary to nature or reason; not adapted to the end; as, a republican government in the hands of females, is preposterous. To draw general conclusions from particular facts, is preposterous reasoning.
3. Foolish; absurd; applied to persons.