Apparently the x is not even pronounced. What's up with that? From Wikipedia:
Spy × Family (stylized as SPY×FAMILY; pronounced "Spy Family") is a Japanese manga series written and illustrated by Tatsuya Endo.
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It follows Hunter x Hunter. See here.
Lin: I just slapped a placeholder name on it at the draft submission stage. Endo-sensei sent in this draft for a serialization without deciding on the title, so we just worked with the title “Spy Family” written in Japanese characters for the time being. And then, when it was actually going to become a real thing, we decided we’d better have a proper name for it. It took us forever to decide on anything! (laughs) I thought “Spy Family” written in Japanese was just fine, but Endo-sensei was worried it was a little too... straight-forward. I swear, he came up with over a hundred names and we went over all of them together. And at the end of it all, we just took the name we had and put it in English characters, with a cross between the words. We talked about how the title of “HUNTER x HUNTER” is super simple, and it how it has the same thing going on.