therefore; for that reason; so
A common conversational conjunction used to introduce a conclusion or result based on what was just said. Often used at the beginning of a sentence.
The train was delayed. So, I was late.
He had something urgent come up. For that reason, he says he can't come today.
A fixed phrase composed of そんな (such) + 訳 (reason) + で (particle indicating means/cause). Literally 'by such a reason'.