Definition from Wiktionary, the free dictionary
black + guard, thought to have referred originally to the scullions and lower menials of a court, or of a nobleman's household, who wore black liveries or blacked shoes and boots, or were often stained with soot.
blackguard (plural blackguards)
- A scoundrel; an unprincipled contemptible person; an untrustworthy person.
- A man whose manners and sentiments are decidedly below those of his class deserves to be called a blackguard.
- Usually, only used to refer to a male person.
- Blackguard may also refer to a man who uses foul language in front of a woman, typically a woman of high standing in society.
scoundrel — see scoundrel
- To revile or abuse in scurrilous language.
- (Can we find and add a quotation of Southey to this entry?)