Can you make a Connectionless Protocol reliable? Why or why not? If so, how?

I mean TCP is connection oriented and it is reliable( by the properties reliability is that it can detect an error by SYNC and ACK signals from source to destination), but UDP (Connectionless) is unreliable because it cant detect errors in the transport layer. So, need question answer that Connectionless protocol reliable or not. If it is reliable or not, I need detailed explanation with certain example.