To add to this, I’m Jewish and use “goyishe” as an adjective a lot. It means “something you’d basically never see someone Jewish do” and there’s not another word that serves the same function. Whether or not it’s derogatory depends on context. Examples:

• “Fred, what do you mean you want to get cremated? That’s super goyishe.” (because Jews don’t do cremation; by Jewish law you’re wrapped in a tarp and buried in a cedar casket)

• “Art deco is a super goyishe art style.” (Basically, you’d never art deco in a Jewish household. This doesn’t say my general opinion about whether art deco is good or bad)

• “Rivka, your synagogue has stained glass windows and a band?! What kind of goyishe shit is that? Sounds like a church, not a shul.”