OED adds terms on a quarterly basis, and last September 8 they added in the range of "Paul Bunnell" to "perfay". There are about 160 new entries (roughly 10% less if you ignore duplications, like having separate entries for 'pearl-dive' and 'pearl-diving'), and about the same number of newly-included phrases were added to existing listings. Most combine familiar words, and sometimes the combination is itself familiar (pay spine, payslip), while others, though unfamiliar, are clearly tecnical terms that I wouldn't expect to know (pectus excavatum).

But a few are completely unfamiliar yet don't look technical. If they are in general, non-specialist usage, I wonder how they became common enough for inclusion, but not common enough that I've ever remotely seen them. (They don't seem to be "only on the other side of the pond" words either.) An example is perduing.

Well, it turns out that I've never heard perduing because it isn't being used currently. OED's only cite is from 1685! (and cites for 'perdue' just as antique).

So why did OED add this antique, unused term that wasn't worthy of inclusion before? What has changed to make it includable now?

Could it be that the OED employee had a quota of words to reach, and in desperation pulled this one up out of the old files?

Very odd. Do you have a way of finding out?

At first glance, there are a couple of things which come to mind. First, it could be the text from 1685 was lost or not available to the OED, and someone came across it and found this word. Second, the word was not clearly understood from the first cite, and was only just understood recently, however absurd that sounds.

quote:

pectus excavatum

This is fairly common to medical people, but I am surprised that it would be included in the OED.