What is the antonym of brief?

The antonym of "brief" depends on the context. Here are some possibilities:

For length:

* Long

* Extended

* Prolonged

* Detailed

* Comprehensive

For time:

* Lengthy

* Extensive

* Durable

* Permanent

For conciseness:

* Verbose

* Wordy

* Rambling

* Prolix

For summary:

* Comprehensive

* Detailed

* Elaborate

The best antonym will depend on the specific meaning of "brief" in the context.