Ask HN How to handle sporadic project information flow?

I am working on a project where the functional specification was not well defined. I'm supposed to be expert enough to make many correct choices myself, but for many things, I still have to ask for clarification. The answers to my questions usually take a few days to return, but sometimes they take weeks. By the time I get the answers, I am not even working on the same task. The information I need comes in so sporadically that I am getting bogged down.

Some of you are probably naturally good at wrapping your minds around this workflow. I'm wondering if there is any specific project management terminology for this situation and are there organizational methods that are published that can help me out.