Inspired by a post on tatzlwurm's LJ:

[spudtater]

Five under-used (and rather arbitrarily-chosen) words which I enjoy too much to let them disappear from the English language:

• Circuitous — roundabout, indirect. "This bus is taking a rather circuitous route".
• Reify — to make an abstract concept concrete, or to regard it as such. "Does love actually have a bona fide existence, or do we just have a tendancy to reify the emotions that we feel?"
• Nadir — the lowest point (opp. zenith). "When I found myself casting a contemplative eye on the medicinal alcohol, I knew I'd reached my nadir."
• Concomitant — existing together with something else. "As well as the major drawbacks of blindness, there are all the concomitant annoyances to put up with, such as the tendancy of people to regard you as incapable or stupid."
• Segue — a motorised personal transportation device using gyroscopes to make a smooth transition from one thing to another. "Our conversation about Glastonbury segued naturally into one about the drugs each of us had had experience of."

Feel free to post similar lists on your own journals — I'd love to see what other people come up with.