Urban Dictionary, for your research
People have been writing definitions on Urban Dictionary since 1999. Each comes with a meaning, an example, and a date. Together, they record what people wanted to explain, and how they chose to explain it.
That collection is available to license for research and language tools. The corpus includes definitions, examples, author credits, dates, and vote counts. Bulk access and ongoing updates are available.
For linguistic research, or a tool that needs to look up what people mean, the data licensing page describes what's available and has a contact form for inquiries.