Whenever someone fraudulently collects money or any other valuable from you, He/She has
scammed you. In Nigeria, scam is most popularly called 419 or yahoo yahoo. What do they mean?

1. 419:

419 is the section of Nigerian law that treats scam related issues. Over the years, scam and fraud have been christened 419.

2. Yahoo Yahoo

During the early days of internet fraud, Yahoo messenger was the primary tool for scamming. Along the line, the unholy act got to be known as yahoo yahoo.

https://burstscam.com/blog/2019/12/31/nomenclatures-of-scam/