(inorganic chemistry) An inorganic compound with the formula CuCl₂.

Alternative spelling of copper(II) sulfate

(inorganic chemistry) The inorganic compound, CuSO₄, which forms blue crystals and is used in agriculture, dyeing, electroplating and many other applications.

(journalism) A copy of a published story and the reporter's notes, kept archived in case of legal challenges etc.

(UK, informal, law enforcement) A corrupt police officer.

(publishing, printing) The copy that serves as the controlling (master) version among a set of copies (as, for example, the master proof to which edits from the authors' proofs are transferred, or an analogous master manuscript with transferred edits).

Menkes disease

(transitive) To send a blind carbon copy to (a person). / (transitive) To send a blind carbon copy of (a message) to somebody.

(rare) brass / chalcopyrite

(grammar) Synonym of shadow pronoun