The basic idea here is that you can easily link to the wikipedia entry for a given topic by putting the [wikipedia]topic[/wikipedia] tag into your post. The tag is replaced by a link that executes the wikipedia search form for that topic.
The plan is to augment this with a mouseover popup containing an excerpt from the wikipedia page.

Wp-Wikipedia-Excerpt

This plugin replaces [wikipedia]topic[/wikipedia] with a wikipedia search link for that term.

Ben Balter

This plugin will work, “as is”, out of the box, but assumes some level of CSS and developer customization to adapt to your site’s specific needs.
Styles can be overridden via your theme’s style.css
Functionality can be overridden via your theme’s functions.php
”Examples”
Don’t display metabox on “product” post type:
<pre><code>add_filter( 'display_custom_fields', 'bb_no_product_metabox' ); function bb_no_product_metabox( $true, $post ) { if ( $post->post_type == 'product' ) return false; return true; } </code></pre>
Don’t display the product_id metakey
<pre><code>add_filter( 'dcf_postmeta', 'bb_no_product_id' ); function bb_no_product_id( $postmeta ) { unset( $postmeta['product_id'] ); return $postmeta; } </code></pre>
Don’t display metabox title
<pre><code>add_filter( 'dcf_heading', '__return_false' ); </code></pre>
Display metabox below content (rather than floated to the right)
<pre><code>add_filter( 'dcf_before_content', '__return_false' ); </code></pre>

Display Custom Fields

Inserts a Wikipedia-like metabox into posts with all the post's associated custom fields and taxonomy terms.

Wp-Wikipedia-Excerpt vs Display Custom Fields