Hi. From the context provided , it quite possibly means wishful thinking; an unrealistic hope or fantasy as put by others here 😊

Good day! I'm going to search for more details, yet your answers could give me a starting point. I'm thankful!

"Idle pipe" doesn't mean anything. "Pipe dream" or "idle pipe dream" both mean the same thing. They mean that it is a half-hearted dream. Or maybe like a kid's dream of being a singer, but not learning how to play music or sing. So, in other words, they have a real dream that they are working hard to achieve.

Hello, you will not find many instances of "idle pipe" and those that you do are going to be completely unrelated to the context of your sentence. This is because the real semantic pair here is "pipe dream." A pipe dream is an unrealistic hope or fantasy. An idle pipe would mean something like a pipe that is not in use. A quick scan of the web search results for "idle pipe" brings me a lot of results from the oil and grass industry.