Picanha is a cut of beef called sirloin cap in the United States that is popular in Brazil. In the United States, it is little known, but referred to as the rump cover, rump cap, or culotte. North American butchers generally divide it into other cuts like the rump, the round, and the loin. In some places in the United States, it is called top sirloin cap. 
In Brazil, the most prized cut of meat tends to be the picanha. There, the fat is retained until the steak has been cooked. In the United States, however, it tends to be removed unless requested otherwise by the customer.
The term “picanha” derives from the word “picana”, which was a pole used by ranchers in the southern parts of Portugal and Spain, particularly in Alentejo, for herding cattle. This herding technique was then taken to Brazil by Portuguese emigrants and eventually the term “picanha” was adopted to refer to the part where the cow was poked by ranchers.