a London particular

a London particular

dated A euphemism for the thick, brown, sometimes lethal fog caused by air pollution in London, especially during the 19th and early 20th century. For many older citizens living London during that time, they could as easily be killed by a London particular as by an attack from a criminal.
See also: particular

a London particular

a dense fog formerly affecting London. dated
This expression is first recorded in Charles Dickens's Bleak House ( 1853 ).
See also: particular