Well, we got a lot going on here. A harbinger is one who foreshadows what is to come. A forerunner. If you contemplate that synonym, you may get a clue as to where 'harbinger' comes from. To be honest, I thought it might turn out to be some kind of bird. But no, a harbinger comes from the 15th century English herbengar, who was someone sent ahead by the military or a monarch to procure lodgings in advance. It's a twist on Middle English herberger, a provider of shelter or inn keeper. It goes back through the French to Old High German and the original compound is heri-- 'army' and berger--'shelter'. In this, it's related the the French auberge, or inn, also with German roots, which explains why it's never sounded very French to me. As time went on, the lodging procurer by imaginative extension became a kind of herald.
'Harbinger' is also related to 'harbor', with its roots of here-- 'army' and beorg--'refuge or shelter'. It seems obvious once you break it down, but hardly so from present day usage.
An interesting little oddity attaches to harbinger. Between herberger and harbinger, you'll notice that somewhere along the way, an -n- was acquired--an intrusive -n- as the online etymological dictionary would have it, and it even directs you to the word 'messenger'. Here you will find that the original word in English was messager. On this point, the dictionary gets quite uncharacteristically grumpy: "With parasitic -n- inserted by c.1300 for no apparent reason except that people liked to say it that way (cf. passenger, harbinger, scavenger)."
Sounds a bit like me when I've failed to plumb the depths of the mystery here.
|A plant called 'Harbinger of Spring'|
All right, so harbingers of spring are all well and good, but as a fair portion of the commenters here are crime fiction readers and writers, this post would not be complete without a harbinger of death. CBS doesn't let you imbed video, but you will find this odd story HERE.