I’ve stumbled across this word at least three times in the last week – once in Umberto Eco’s "The Mysterious Flame of Queen Loana", once in reference to the London bombings, and once in some report on NPR. It’s an interesting word, and now that I’ve heard it several times, and now written about it, I’m sure it will become part of my permanent vocabulary.
There is now even a heavy metal band called Threnody. This makes sense. The term is similar phnoetically to the more familiar "trinity", but with darker meanings. Threnody is one of those interesting archaic terms that seems to now be used only in religious terms. Another good one is "panoply", referring to a display of armaments. About the only time one encounters these terms now is within traditional hymn texts, such as the "panoply of God" as referenced in the martial hymn, "Soldiers of Christ, Arise!". Both are fascinating terms, and I may try to use one in the title of my new novel.