Osa (|| | | |) is the eighth Odu on the list of the sixteen principal Odu in Ifa oracle divination system. It is comprised of a double line in the first position and single lines in the second, third and fourth positions.
Note that in most cases, the sixteen Odu are arranged from down to the top starting from Oyeku to Ogbe.
The double line is a split side of a cowrie and the three single lines are the split sides of three cowries.
A split side is equal to 0 and a smooth side is equal to 1, such that Ose (|| | | |) is equal to 0111.