Definitions aren't the specialty of philosophy. For definitions, you should turn to a lexicographer.

If philosophy has taught me anything, it's that not everything that looks like a question and feels like a question and seems like a question is actually a question. I know you aren't asking for a link to merriam-webster.com, so what is it really that you think you're asking for? What are you trying to determine?

I think "everything" doesn't have a logical definition. Like in mathematics you can define "everything" within a system with the equation x=x (at least in first order systems). But there will always be objects outside the system.