crud

n. layer of dirt or filth

Crud may refer to:Crud (game), played on a billiard tableChalk river unidentified deposits, which form on nuclear test fuelsCreate, read, update and delete (CRUD), basic functions of a computer databaseCrud, as a minced oath or in the sense of dirt, or a euphemism for crap
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Noun
1. heavy wet snow that is unsuitable for skiing
(hypernym) snow
2. any substance considered disgustingly foul or unpleasant
(synonym) filth, skank
(hypernym) waste, waste material, waste matter, waste product
3. an ill-defined bodily ailment; "he said he had the crud and needed a doctor"
(hypernym) disease

(n.)
See Curd.
  

A colloquial term for corrosion and wear products (rust particles, etc.) that become radioactive (i.e., activated) when exposed to radiation. Because the activated deposits were first discovered at Chalk River, a Canadian nuclear plant, "crud" has been used as shorthand for Chalk River Unidentified Deposits.