Orljava is a river in Slavonia, eastern Croatia, a left tributary of Sava. It is 87.6 kilometres (54.4 mi) long and its basin covers an area of 1,618 square kilometres (625 sq mi).[1]
There are several etymologies suggested for the hydronym. One is that it comes from the Croatian word "oriti", meaning "echo". The other is that it comes from the Indo-European root *h1or, meaning "to flow". If so, then the same root is seen in the hydronym "Raša".[2][unreliable source?]