Computing term for a program that translates source code into machine code or another language. The English gloss 'compiler' is standard, but note that 翻訳ルーチン can also refer more broadly to a translation routine.
This compiler translates C source code into assembly.
翻訳ルーチンの最適化によって実行速度が向上した。
The execution speed improved due to optimization of the compiler.
Compound of 翻訳 (translation) and ルーチン (routine), a direct calque from English 'translation routine' used in early computing.