Castles in air and Preposterous

Preposterous and castles in air are semantically related. in imaginary topic. In some cases you can use "Preposterous" instead an adjective phrase "Castles in air".

Preposterous adjective - Conceived or made without regard for reason or reality.

Castles in air and preposterous are semantically related. Sometimes you can replace phrase "Castles in air" with "Preposterous", this terms are similar.