Brig

Meaning: Prison; detention center.

Brig is a US military term with one of two uses:

A jail or prison on board a U.S. Navy or Coast Guard vessel.
A jail or guardhouse, especially on the premises of a U.S. military installation.

Galactica seems to have originally possessed two brigs. One has at least two small cells with bunks. The other brig has one larger cell with no commodities for high-security prisoners. In the episodes in which the brigs have made appearances, there is usually a Marine guard standing watch inside the room. In the high-security brig, there are usually around four.

After Galactica-Boomer was revealed as a Cylon, Colonel Tigh ordered a third custom-made super-reinforced brig constructed. It was built for the specific purpose of containing captured Humano-Cylons, who possess strength far greater than a human's, for an extended period (Resistance). The new brig was constructed with maximum security in mind; instead of having simple bars, its walls consist of metal grid screens welded tightly together, reinforced by plexiglass (a telephone is used to communicate between the inside and outside of the cell). After being brought to Galactica, Caparica-Boomer was detained within the new Cylon-brig cell. Number Six claims that Sharon's hybrid daughter will be born in this cell (Home, Part II).

Notable chracters who have spent time in the brig are:

Season 1

Starbuck -- striking a superior officer in the Mini-series
Aaron Doral -- under suspiscion for being a Cylon agent in the Mini-series
Specialist Socinus -- lying under oath and leaving a post in Litmus and is released in a deleted scene in Kobol's Last Gleaming, Part I
Gaius Baltar -- act of treason, allegedly collaborating with the Cylons in Six Degrees of Separation
President Laura Roslin -- consequence of a successful coup d'etat led by Commander Adama in Kobol's Last Gleaming, Part II
Apollo -- mutiny in Kobol's Last Gleaming, Part II and appearing in Scattered. He is able to be let out of the brig when on duty.

Season 2

Galactica-Boomer -- shooting a superior officer in Kobol's Last Gleaming, Part II and appearing in Scattered
Chief Tyrol -- under suspicion of conspiring with Galactica-Boomer, in Resistance
Cally -- for "discharging a firearm without permission" (killing Galactica-Boomer in a crowded hallway) in Resistance and appearing in The Farm
Caprica-Boomer -- Permantly detained (for being a Cylon) in the new custom-built Cylon holding cell in Home, Part II.
Joe "Hammerhead" Palladino -- Attempted murder of a superior officer ("Final Cut")