MAX: Well, I’m glad to hear it. And Rory’s good?
LORELAI: Oh, yeah, she’s the Encyclopædia Britannica definition of good.
Encyclopædia Britannica, (Latin for “British Encyclopædia”) is a general knowledge English-language encyclopædia, first published in the 18th century in Edinburgh, Scotland. Though published in the US since 1901, the Britannica has for the most part maintained British English spelling. Since 2016, it has been published exclusively as an online encyclopaedia.
If you look up “Good” in the Encyclopædia Britannica, you will find an article on Gnostic philosophy and spirituality, where the Good is a transcendent deity. Probably not what Lorelai was thinking of!