metalanguage
Technical term in linguistics and logic for language used to describe or analyze another language.
In linguistics, metalanguage is sometimes used to explain grammar.
論理学の授業でメタ言語の概念を学んだ。
I learned the concept of metalanguage in a logic class.
From English 'metalanguage', combining the prefix 'meta-' (beyond) with 'language'. The Japanese form is a direct loanword adaptation.