What is a Gulliver in British slang?

I'm curious, what exactly is a Gulliver in the realm of British slang? Is it a term used to describe a particular person or situation? I'm eager to understand its origins and how it's typically employed in conversational settings. Could you elaborate on its meaning and provide any examples of how it might be used? I'm intrigued by the nuances of language and how they vary across different cultures and regions.