While I don't believe a person can be too-Jewish, especially not in this modern age, it's possible that I speak a slightly different language from some people.
So I just had a hysterical phone conversation with a blog-friend (not Jewish), who pointed out that there's been an increase in words he doesn't understand, recently, but he does enjoy working out what they may mean. And I tell him that I think some of my yiddishisms are relatively obscure, and probably a lot of Jewish people don't get them, either. And also, since I stopped italicising Yiddish/Hebrew words, as I'm no longer prepared to other my heritage, it's probably a lot harder to tell what's Yiddish and what's a typo.
"So," he says to me, "you're getting more frum. I've been wondering what that means, from the context."
"Go on," I encourage him.
"Well, I've decided that it means traditionally devout. It's a great word. Kinda sounds like prim."
And, while frum is often translated as observant, or relgious, I think traditionally devout is better. Although it goes without saying that I feel neither traditional or devout. I mean, I know people so much more traditionally devout that me, that comparatively, me with my post-denominational flexible approach, I can hardly call myself frum.
Which just goes to show maybe outsiders-looking-in have a better idea about what things mean than people on the inside.