Definition of "reification"
noun
countable and uncountable, plural reifications
(programming) A process that makes a computable/addressable object out of a non-computable/addressable one; or a concrete class out of a generic one.
Quotations
Contrary to Java, C++ and C# implement generics via reification, meaning that each specific version of a generic class, like List<String> is converted into a concrete class, either at compile time (C++) or at runtime (C#).
2020, Marco Faella, Seriously Good Software: Code that works, survives, and wins, Simon and Schuster, page 251