I've already written several posts about slang and colloquial terms used during the Regency era, but I have barely scratched the surface. There are so many that I would still like to share with you. So, here are some taken from the 1811 Dictionary in the Vulgar Tongue:
Back Biter: someone who slanders another person behind their back.
Crack a whid: to tell a tale.
Fallalls: women’s accessories, such as jewellery or ribbons.
Grumbletonian: a person who is always complaining about one thing or another.
Postilion of the Gospel: a parson who hurries over the service.
Quiz: a strange-looking person.
Sauce box: a forward or bold person.
To cry beef: to give the alarm.
To milk the pigeon: to try something impossible.
Tongue enough for two sets of teeth: someone who talks a lot.
To take French leave: to go off without taking leave of the company; it usually refers to people who run away from their creditors.
Tuft-hunter: someone who courts the acquaintance of the aristocracy.
Unlicked cube: a rude and uncouth young person.
Further reading:
How People Spoke: The Regency Era
How They Spoke: The Regency Era (Part 2)
Regency Slang