Preposterous and Self-willed

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

Self-willed and preposterous are semantically related In some cases you can use "Self-willed" instead an adjective "Preposterous".

Self-willed adjective - Sticking to an opinion, purpose, or course of action in spite of reason, arguments, or persuasion.

Preposterous and self-willed are semantically related in disorderly topic. Sometimes you can use "Preposterous" instead an adjective phrase "Self-willed".