Find the word definition

Wiktionary
managed code

n. (context computing English) source code that will execute only under Microsoft's Common Language Runtime.

Wikipedia
Managed code

Managed code is computer program source code that requires and will execute only under the management of a Common Language Runtime virtual machine, typically the .NET Framework, or Mono. The term was coined by Microsoft.

Managed code usually refers to programs written in .NET languages such as C# or Visual Basic .NET, while unmanaged code refers to programs written in C, C++, Visual Basic 6 and other languages that do not need a runtime to execute.