A
pig. The
Fuzz. A
rozzer. A
bobby. A
copper. A
police constable.
A mildly derogatory slang term used in London and possibly elsewhere, of uncertain origin. In old-fashioned English a raddock or ruddock can be a robin or a gold coin - "probably because the gold of coins was often reddened by copper alloy" says Webster 1913 - so there may be some connection with the term copper.