What does "blackguard" mean?

Blackguard: The criminals and vagrants or vagabonds of a town or community, collectively. [Obs.]

Additional senses

  1. 2.A person of stained or low character, esp. one who uses scurrilous language, or treats others with foul abuse; a scoundrel; a rough. A man whose manners and sentiments are decidedly below those of his class deserves to be called a blackguard. Macaulay.
  2. 3.A vagrant; a bootblack; a gamin. [Obs.]
  3. 4.To revile or abuse in scurrilous language. Southey.
  4. 5.Scurrilous; abusive; low; worthless; vicious; as, blackguard language.

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