The word "bureau" comes from the French "bureau", meaning "desk" or "office", which itself comf from the Old French "buret", meaning a course woolen cloth.  This cloth was used to cover writing desks, and the name of the covering eventually transferred to the desk itself. The term ultimately traces its roots back to the Latin "bura," referring to a shaggy cloth or a type of coarse wool, and the Greek "pyrros," meaning "flame-colored". 

In North American English, a bureau is a chest of drawers.  In British English, bureau is a writing desk with drawers and typically an angled top opening downward to form a writing surface.  A bureau can also be an office or department for transacting particular business. 

Examples of "bureau" (as a piece of furniture) in a sentence: 
"Cynthia was standing at her bureau for a last minute comb of her hair." 
 "He placed the bone atop Cynthia's jewelry box on their bureau and climbed into bed." 
"Dean crossed to the bureau picked up his hairbrush."

Examples of "bureau" (as a division of government) in a sentence: 
"That's the Colorado Bureau of Investigation, the State cops." 
"He represented the United States Bureau of Education at the International Congress of Educators at Brussels in 1880." 
In 1868 the International Bureau  of Telegraphic Administrations was constituted at Berne, and a convention was formulated by which a central office was appointed to collect and publish information and generally to promote the interests of international telegraphy." 

In Australia we have the Bureau of Meteorology, which as you would expect provides our weather forecasts. Their web address is www.bom.gov.au and, much to the annoyance of the Bureau, they are referred to simply as Bom. An interesting twist is that the Bureau recently launched a new website which is very unpopular and regarded, by a lot of Aussies, to be a bomb.