Scoundrelly
Scoundrelly is an adjective that describes behavior or a person characterized by roguishness, dishonesty, or lack of integrity. It often implies a certain charm or cunning that allows the individual to get away with their questionable actions. A scoundrelly act is typically one that is selfish, underhanded, or morally dubious, often to the detriment of others.
The term can be used to describe a wide range of misconduct, from minor deceptions and trickery
The etymology of "scoundrel" itself is somewhat uncertain, but it gained currency in the English language around