How is “elephant in the room” used?

In Glass Onion: A Knives Out Mystery (2022), one line is: “Are we even gonna talk about the elephant in the room?”

Which movie is “elephant in the room” from?

The clip at the top of this page is from Glass Onion: A Knives Out Mystery (2022).

Are we even gonna talk about the elephant in the room?

8 作品で登場 · 1 本目

a problem or question that everyone knows about but does not mention because it is easier not to discuss it

12 本の映画に登場定番表現を再生

オックスフォード映画の 100%
a problem or question that everyone knows about but does not mention because it is easier not to discuss it
Are we even gonna talk about the elephant in the room?
And it's a bit of an elephant in the room, and I think it's time we discuss it.

定義：Oxford Advanced Learner's Dictionary 第 9 版