that is (to say)

成語所屬單字that

that is (to say) — 慣用語

1. used to explain what you mean more clearly or to correct or add detail to what y

1.慣用語
釋義

也就是說

used to explain what you mean more clearly or to correct or add detail to what you have just said.

例句

We leave on Friday — that is, the fifteenth of June.

The plan needs to be cost-effective, that is to say, it must not cost more than it saves.