What is an antonym for chamber?

There isn't one perfect antonym for "chamber" as its meaning can vary depending on context. Here are some possibilities, depending on the intended meaning:

If "chamber" refers to a room:

* Open space

* Hallway

* Exterior

* Outdoors

If "chamber" refers to a confined space:

* Vastness

* Expanse

* Openness

If "chamber" refers to a part of a device:

* Exterior

* Outer part

* Open area

If "chamber" refers to a legislative body:

* People

* Citizens

* Public

Ultimately, the best antonym will depend on the specific context in which you are using the word "chamber".