What does "the elephant in the room" mean — and why is it funny?

informal

Meaning

An obvious, important problem that everyone present can see but no one wants to mention.

Where it comes from

A twentieth-century phrase that has steadily become one of the most common ways to name an awkward, carefully avoided subject.

Why it is funny

The humor is the sheer scale of what is being ignored. The phrase asks you to imagine a full-sized elephant filling a living room while everyone politely discusses the weather, and that absurd, strained politeness is the joke.

Used in a sentence

"We chatted for an hour and nobody mentioned the elephant in the room — the company is closing."