Calque of French de cape et d'épée (“of the cloak and the sword”); first attested 1840. The French term referred to a genre of drama in which the main characters wore cloaks and had swords. Henry Wadsworth Longfellow used the “cloak and sword” term in 1840, whereas Charles Dickens preferred “cloak and dagger” a year later.
- Marked by menacing furtive secrecy, often with a melodramatic tint or espionage involved.
- Israel wages cloak-and-dagger war on Iran — headline, The Age, February 18, 2009 by Philip Sherwell and Dina Kraft 
- See also Thesaurus:covert