Why was the underground called the clockwork orange?

The term "clockwork orange" in the context of Anthony Burgess's novel refers to the idea of a mechanized society that suppresses individuality and free will. The phrase suggests a juxtaposition between the natural and the artificial, symbolizing the conflict between human nature and societal control. The underground movement in the story represents a rebellion against this oppressive system, highlighting the struggle for personal freedom in a conformist world.