schmutzdecke
n.— «Periodically the top layer of sand (approximately 25 to 100m deep) needs to be removed from the slow sand filters together with the associated biological accumulation (“schmutzdecke”) for cleaning.» —“Tender—Department Of The Environment For Northern Ireland Water Executive—Central Design Unit” Contract Journal January 27, 1994. (source: Double-Tongued Dictionary)
Further reading
An upscuddle, also spelled upscuttle, is defined in both the Dictionary of American Regional English and the Dictionary of Southern Appalachian English (Bookshop|Amazon) as a type of quarrel. A 1913 reference uses the term this way: “If they...
Cat hair may be something you brush off, but cat hair is also a slang term that means “money.” In the same way, cat beer isn’t alcoholic — some people use cat beer as a joking term for “milk.” And imagine walking on a...