Preposterous is an adjective that is used to describe something which is foolish or silly. Contrary to common sense. Absurd, senseless.
- After all that he had done wrong, he tried to justify his actions with ‘preposterous’ excuses.
- He came up with a ‘preposterous’ idea, about how to change the direction of the company.
- She was acting ‘preposterous’, but in reality she knew all the information regarding the situation.