Strangely, "bastardly" is not a word, but the same meaning is served by the term "dastardly." Once a serious insult, dastardly is now almost always used sarcastically. If used seriously, the speaker is most likely a nancy boy and/or fop. It is generally used in the phrase "dastardly deed(s)."

A sarcastic name for singer and songwriter Dua Lipa

The main character from classics Hanna Barbera cartoons Dastardly & Mutley in Their Flying Machines and Wacky Racers.

In Dastardly & Mutley in Their Flying Machine, Dastardly tries to catch a pigeon with your squad.

In Wacky Racers, Dastardly is a racer of 00 car and always tries to retire your opponents of race for win.

Also in some regions, refers to Michael Schumacher because your controversial moves in some races in F-1.

to describe something that is quite related to a dastard.