I too think it is something very serious. Many seam to use the term any time anyone is killed. How do you define a Martyr?
That's really a great question.
Perception is everything, of course, but I've always understood martyrdom to be based on dying for "the cause" at the hands of others...not the self-inflicted variety.
There's all sorts of honor accorded those who willingly lay down their lives in defense of (
insert cause here)...the ultimate sacrifice.
I'd guess that's the mainstream opinion as well, at least in western societies, where I was raised and now live.
The idea of being or not being afraid to die is an interesting one I think. Nature has preprogrammed successful animals with a desire to survive, and once you add our ability to have a sentient perception of death, you have a formula for a more deep seated fear (at least, one that can be expressed by doing something more than just fleeing, like all other animals do).
Suicide on the other hand, is taught to be the "coward's way out" and, from the theists' points of view, the usurpation of god's role in taking something that isn't really "yours". To commit suicide in a fashion that also takes the lives of other innocents is, of course, abhorrent to all societies...except fundamentalist jihadis.
While they certainly didn't invent suicide bombing as a tactic, jihadis are the ones saying these heinous crimes are legitimate, even honorable and praiseworthy, simply because they have changed the definition of mass murder/suicide to martyrdom.
We all fear death yes, since no one knows what lies beyond that event...if anything. (Truth be known, I'll bet every fetus is scared xxxxless at the idea of
birth, for the same reasons). Most likely death is simply "nothing", but that is as peaceful an eternity as any promised by religion.