blackguard a man who behaves in a dishonourable or contemptible way. The term originated (in the early 16th century) as two words, black guard, denoting a body of attendants or servants, especially the menials who had charge of kitchen utensils, but the exact significance of the epithet ‘black’ is uncertain. The sense ‘scoundrel, villain’ dates from the mid 18th century, and was formerly considered highly offensive.

black·guard / ˈblagərd; ˈblakˌgärd/ • n. dated a person, particularly a man, who behaves in a dishonorable or contemptible way.