I think combination or combined is still your best fit.
combination (n) a collection of things that have been combined; an assemblage of separate parts or qualities
There are two programming languages that has "combined" in their name. There is a combination of features in them.
- CPL (Combined Programming Language)
- BCPL (Basic Combined Programming Language)
CPL ( Combined Programming Language ) was developed with the purpose of creating a language that was capable of both high level, machine independent programming and would still allow the programmer to control the behavior of individual bits of information.
Mixed can be used also.
mixed adj. incorporating different systems or elements
There is a specific programming term:
Mixed-language programming is the process of building programs in which the source code is written in two or more languages. Although mixed-language programming presents some additional challenges, it is worthwhile because it enables you to call existing code that may be written in another language.
Mixed language is used in linguistics also:
A mixed language is a language that arises through the fusion of usually two source languages, normally in situations of thorough bilingualism (Meakins, 2013), so that it is not possible to classify the resulting language as belonging to either of the language families that were its sources.
As this is related to programming, you might be asking for "multi-paradigm" language as well:
A multi-paradigm programming language is a programming language that supports more than one programming paradigm.
As Leda designer Timothy Budd puts it: "The idea of a multiparadigm language is to provide a framework in which programmers can work in a variety of styles, freely intermixing constructs from different paradigms."
The design goal of such languages is to allow programmers to use the best tool for a job, admitting that no one paradigm solves all problems in the easiest or most efficient way.
A programming paradigm is a fundamental style of computer programming, a way of building the structure and elements of computer programs.
Capablities and styles of various programming languages are defined by their supported programming paradigms; some programming languages are designed to follow only one paradigm, while others support multiple paradigms.
Lastly, you cannot directly combine different languages because there are different calling conventions and compiler operations.
Here are more details: