What is taint analysis? I just came across the term "taint analysis" in a crypto-related conversation. 

This came up while discussing "tracking bitcoin transactions" so it's somehow related to that. That's all I know.
The “taint” of a Bitcoin transaction evaluates the association between an address and earlier transaction addresses. The more “‘taint” the stronger the link between the two addresses. 

https://bitcoin-class.weebly.com/taint-analysis.html