Question

why wouldn't the word translation be used to describe mRNA synthesis?

Answer 1

Beeeecause we already have a different word for mRNA synthesis.

"Transcription."

~~~

"Translation" is where we take mRNA,
and we use it to synthesize amino acids.

Answer 2

Because transcription would be the correct term. In translation, the mRNA has already been synthesized and is used to create amino acids for ribosomes and then eventually shipped off into the golgi apparatus to be packaged.