ObjectGraph allows you to find definitions based on a word list using a version of the 1913 edition of Webster's Unabridged Dictionary (about 200,000 words) or the Free Online Dictionary of Computing (about 14,000 terms).
Btw, in this December blog post, I pointed out two other services: AOL's PinPoint Shopping and the LookAhead News Index from Surfwax that also offer dynamic search term suggestions. AOL's tool has been online for several months while LookAhead News has been available for about a year. Worth a look.
Meet Your Favorite Search Engine Watch Contributors
Many of SEW's leading expert contributors will be at ClickZ Live, the new online and digital marketing event kicking off in New York (March 31-April 3). Hear from the likes of: Thom Craver, Josh Braaten, Lisa Barone, Simon Heseltine, Josh McCoy, Lisa Raehsler, Greg Jarboe, Dan Cristo, Joseph Kerschbaum, John Gagnon, Eric Enge and more!