Hmmm, this is an insteresting question. I would say it is possible but is going to be very difficult for most generic search terms like single dictionary words.
I was wondering if going into the wikipedia article and then disconnecting the internal links would help. What do you think?
it all depends on your niche. the only way that i can think of is .. lol, build more backlinks, have better contents, good link baiting campaign is the key here! Provide a tool that every other site in your niche needs, that will enable you to gain backlinks faster than the wiki page.
You can knock wikipedia down temporarily using the proxy linking technique. Kinda black-hat stuff though.
Why knock down Wikipedia? Why not ride on its back? Make an article there, and it's possible it'll be on the first page on Google.
Proxy linking techniques are something best avoided as you'll be banned from the search engines (or your site will be anyway) if and when (emphasis on the "WHEN" part) you get caught.
It's a black-hat technique that will just get you in lots of trouble. Something on the scale of stealing the Magna Carta or the Declaration of Independence - but without the treasure (and a long prison sentence instead).
Only way would probably be to use gray hat or black hat techniques. You can also try to get a link on that wiki page, that may help?