Nacreous sounds like it should relate to the appearance of a festering wound.

it does in some ways, since the pearl (and mother of pearl) is formed by specialized cells at the edge of the oyster, and a pearl of is an attempt by the oyster to seal of an irritant. a pearl is evidence of a festering irritant!

crossing thread, the cruciverbalist on the board all knew nacre-- its a fairly common crossword word.. along with Nick and Nora's Dog, (Asta) or FDR's dog (Fala), just as we know what a wapiti is!
an elk


my other obsession