There are a few meanings to the term indie. The first is independent, like zeebra said. At that point of time, there were quite a number of indie bands. Early nirvana was one, so was blur, stone roses, the inspiral carpets and suede. It eventually got broken up into 2 main types. The grunge, pre grunge of the pixies, nirvana, breeders, dinosaur jr etc. american version of the indie pendent bands and the british version of indie, stone roses, charlatans, ned's atomic dustbin etc. Though shoegazer bands were indie, they were mostly just referred to as shoegazer --- mbv, ride, curve, jesus and mary chain. Then the british bunch became known as brit pop as most of the shoegazer bunch died out and the american bunch became grunge even though guys like soundgarden aren't exactly grunge. The term indie pretty much died out.
But in singapore, now, most of the time, indie bands usually refer to the brit version of indie. But with the advent of easy electronics, bands which have the electronic and indie sound are known as indietronica. Since most bands in britain now fall under either a version of brit rock/pop, punk, shoegazer, it's very seldom anyone refers to bands as indie anymore in any other place except here, or trying to reference that old school british indie sound of the 90s.