I never saw this word before, and have not seen "sprue" for over thirty years.Another
crazy spelling bee word. I thought it might be related to psilocybin.
From xRefer
sprue (psilosis) n.


deficient absorption of food due to disease of the small intestine. Tropical sprue is seen in
people from temperate regions who stay in tropical climates for weeks or months. It is
characterized by diarrhoea (usually steatorrhoea), an inflamed tongue (glossitis), anaemia, and
weight loss; the lining of the small intestine is inflamed and atrophied, probably because of
infection. Treatment with antibiotics and folic acid is usually effective, but the condition
often improves spontaneously on return to a temperate climate. See also coeliac disease
(nontropical sprue), malabsorption.

I love words that develop from different languages:

sprue1
n.

A chronic, chiefly tropical disease characterized by diarrhea, emaciation, and anemia, caused by defective absorption of nutrients from the intestinal tract.

[Dutch spruw, from Middle Dutch sprouwe.]


sprue2
n.

1. The hole through which molten material is chanelled into a mold.
2. The waste material filling or protruding from this hole after hardening.
3. The usually plastic rod or framework that secures molded objects, such as model parts or game pieces, before their first use.

[Perhaps of Scots origin.]

(from Atomica)