Admittedly, not a word you would hear often these days but this post hopes to change that again.
Blümerant means as much as “oddly unwell”, “out os sorts” or “green about the gills” as in Mir is janz blümerant.

The word - which is considered to be a threatened piece of German vocabulary and was even included in a list of words worth preserving because of their cultural connotations - is, like so many other German and especially Berlin words - a distorted form of a French word or phrase: bleu mourant.

Itself a combination of “blue” and “looking as if about to die” it must have appeared around the time of the big cholera epidemics in Europe. Famously, one of the symptoms of approaching death among the infected was their skin turning more or less strong blue hue. Hence blue mourant and the once so popular in Berlin blümerant (sometimes pronounced plümerant).
that's a good one!