This plugin only half-works, but this is a good begining:
1 - it add a footer link outside the theme and broke it, just comment the line...
2 - the highlight is really not optimized:
- doesn't support HTML so it's break your code if the lexicon-entry is in a html tag
- doesn't take care of upper / lowercase when highlight
- doesn't take care of accentuation
- no class is define to personalize the link
The shame is all this can be assumed in the regex preg_replace, i.e.:
$content = preg_replace('/((?![^<]+>)'.$result['post_title'].'(?![^<]+>))/i', '<a class="lexicon" href="'.get_permalink($result['ID']).'" title="Definition: '.$result['post_title'].'">$1</a>', $content, -1);
corrects all
(Pardon my French... oops my English!)