by definition

According to, or as a matter of, definition. / Necessarily; always; certainly.

日本語の意味

定義によれば / 定義上は / 必然的に / 常にそのように

A bachelor, by definition, is an unmarried man.

定義上、独身者は未婚の男性です。

意味（1）

According to, or as a matter of, definition.

意味（2）

Necessarily; always; certainly.

Almost by definition, a conversation requires both parties to accept each other's viewpoints to some extent.