Now, I didn't read the whole thing (spoilers for I show I've already watched but am re-watching right at the beginning of the article's subject) but there is an impressive post about Willow and Tara's relationship (starting in season four of Buffy the Vampire Slayer) and the relationship's relationship to doors, here, at a kind of astounding blog called This To Say About That that I learned about today through whedonesque.com.
In the post (which surely deserves to be called an 'article') I encountered the word liminal for the first time. Yes, I am a little embarrassed about that. Turns out it means, in part, threshold, which is pleasing Anglo-Saxon looking word that I wanted to know more about--I wanted the Anglo-Saxon roots to be transparent to me. This is how I am with words.
The etymology of threshold is murky and doesn't really offer up its secrets, but the American Heritage 4th ed. does send us to the Indo-European root (that I don't know how to display properly) that is pronounced just like Tara.
I know, right? But that's not all. The first definition for that root is to rub, as in tribade--as in the the band Tribe 8, or as it appears in Gene Wolfe's Book of the New Sun (where I learned it), tribadist.