First of all, the reason for asking here instead of looking up the Wikipedia page probably makes sense, since Wikipedia often has its own copyright issues. However, remember that here at SitePoint, we don't give legal advice and you are ill advised to rely solely on the advice of members, including me.
On their page, they talk a lot about the US Copyright "fair use doctrine". They get away with a lot of fair use because they are a non-profit encyclopedia. If your site is monetized in any way, you probably won't. Fair use is not a right, it's a defense. The accuracy of fair use is determined by a judge, in a courtroom, case by case. In other words, if you are sued for plagiarism, and say to the judge "It was fair use". He might look at you, smile, and say "No it isn't."
If you want to use Wikipedia information on your page, this link is the place to start. Read the instructions, follow the directions and the various links to definitions and the fine points of reuse of Wikipedia content. It may take you an hour or two, but just consider it a part of your job in developing a web site.
Finally, what gain do you perceive you'll get out of using their copy on your site? If you don't follow their directions and use their copy word for word, in addition to plagiarized content you'll also have a site that is full of duplicate content, which is something that may result in search engine penalties or outright banishment from their indices.
Moreover, if you're developing a website, make it your website. If your visitors want Wikipedia information, chances are they already know where to get it... and you most probably will never outrank Wikipedia in search engine results.
You are better off to fill your site with original content that is directly targeted to your target market.