I'd like to start a thread for words whose discovery was an occasion of surprise and wonder. I am talking about not only about the thrill that comes with the dilation of the frontiers of the namable world, but also that frisson of discovery, when a word introduces you to an object, phenomenon, concept which had been sitting in front of you all along, but which you might never have otherwise actually noticed. And I'm not necessarily talking about fancy-pants or gimmicky words. Just whatever word has given you a big "ah-ha".

Either you're a word-nerd, and know what I am talking about, or you'd best "tsk tsk" and go elsewhere. But perhaps an example would help, to kick off what will hopefully be an interesting pooling of favourite lexicon:

suprasternal notch (yes, thank you 'The English Patient')
lambdoidal (because A-frame needs a lintel)
palatine uvula (no more "little dangly bit at the back of my throat")
dendroid (it blows "tree-shaped" out of the water)
meniscus (and it's convex if the glass is dry!)
torus (without it we have a theory of a "doughnut-shaped space-time curvature")
noctilucent cloud (google it. they're beautiful cloud)
lenticular image (try explaining this any other way)
lacrimal caruncle (in the lacrimal lake! of course)
linea nigra (every parent will remember this)
pollarded (I walk to work down an arbour of pollarded oaks... only recently learnt it)
garth (where I eat my lunch, surrounded by a cloister)

Anyway, that's my offering... I could go on, but in the sad event this thread bombs, I'll regret wasting my time...

Stag.