blackguard

The lowest servant in a household charged with pots, pans, and other kitchen equipment.historical

An unprincipled, contemptible person; an untrustworthy person.dated

• 1830, Thomas Macaulay, Review of Robert Southey's edition of Pilgrim's Progress, in the Edinburgh Review A man whose manners and sentiments are decidedly below those of his class deserves to be called a blackguard.
• 2006,' Jan Freeman, Blaggards' of the year – Boston Globe "Arrr, keelhaul the blaggards!" wrote Ty Burr in the Globe last summer, pronouncing sentence on the malefactors who brought us the second "Pirates of the Caribbean" movie.

A man who uses foul language in front of a woman (typically a woman of high standing).archaic

To revile or abuse in scurrilous language.transitive

• Persons who passed each other in boats upon the Thames used to blackguard each other, in a trial of wit
• The Southern Region takes, in the main, a candid line with its public. […] An ill-informed attempt to blackguard the railway publicly is likely to see the complainant put politely—but very firmly—in his place.

To act like a blackguard; to be a scoundrel.intransitive