Frankly, I’ve never been much of a fan of Halloween, I don’t think that it was really much of “a thing” in 1960’s England. Or maybe that was just our family. Anyway, these days it is huge, presumably from the influence of the USA & the retail opportunities that flow from it. I was in Peterborough recently & walked past “The Halloween Warehouse”!
I see that one definition of the “Undead” is “no longer alive but animated by a supernatural force“.
What a happy coincidence as by swapping a few words it seems to make a rather good definition of the “Unretired”:
“No longer in PAYE employment but animated by a powerful force (to do good).”