Luminiferous aether means light bearing aether (lumini - light, ferous - bearing or conveying) - a medium through which  light propagates.

The  origins  of this theory were  the experiments that showed that light behaves like  a wave.  Because all other waves propagated through some kind of  medium, it was hypothesized that there must be a medium through which light wave traveled. The properties of this medium were unclear, and thus were  debated throughout the 19th century.

To understand the needed properties of this medium, we must first understand the origins of the term aether. Then we will look at the  history of light and wave physics, from which we will be able to understand the properties of the aether.