Bottomless pit - How can a pit be bottomless? Well, this idiom is a bit funny but it means good. If you have a bottom of something then if you pour something in it, it will fill but if something does not have a bottom, it won't fill ever, and especially when you compare it with a pit (it's funny). This idiom means that someone or something is never satisfied with what he/she/it has, and wants more, especially money.
1. I think this project is a bottomless pit, how much do we need to invest?
2. You are a bottomless pit John, I had given you 10 chocolates just last hour, and again you're asking me for it.
3. Well, Chinad, you are a bottomless pit, how many dresses you want to buy, I don't know.