Have you ever seen someone trying to solve a problem by looking at two different things that don't seem to be related at all? That's kind of like what "seemingly unrelated regressions" means.
In math, we use something called "regressions" to help us understand the relationship between two different things. For example, we might want to know if there's a relationship between how many hours of TV you watch per day and how well you do on a math test. We can use regression to help us figure that out.
But what if we want to look at two things that aren't really related to each other? Like, what if we want to see if there's a relationship between how much rain falls in a certain area and how many cars are sold in that same area? Those two things don't seem to have anything to do with each other, right?
That's where "seemingly unrelated regressions" come in. Instead of trying to force a relationship between those two unrelated things, we can use two different regressions to try to understand them separately. That way, we're not making any assumptions about a relationship that might not actually exist.
It's like if you're trying to solve two different puzzles at the same time, and you realize that the pieces from one puzzle aren't going to fit into the other one. You need to work on each puzzle separately to figure them out.
So, in summary, "seemingly unrelated regressions" is a fancy way of saying that we're using two different regressions to understand two different things that don't seem to be related to each other. We can do this so that we don't make any assumptions about a relationship that might not actually exist.