I will say that breviary it showed up in "advanced" for me, and was one of only two words below "grandmaster" I missed. In the modern era it is jargon, it's just that the in group (practitioners of liturgical Christianity) are in the ballpark of a quarter of the English speaking world.

I'll remark that "if you have interest in [some particular academic pursuit], you'd likely know it" is a pretty decent description of the sort of word that shows up in "grandmaster" tier.

(I have joked that, living in Japan, my English is getting worse faster than my Japanese is getting better, but breviary might well be a concrete example.)