Acronym Manager is the new plugin in WordPress Plugin Repository that lets you define your own acronyms and your can display them inside your blog posts, pages and even in comments by using a simple markup tag.
Installation & Usage: Install and activate Acronym Manager. After activation visit your admin area Dashboard -> Tools -> Acronym Manager page and here you can add new Acronyms and their definitions, its as simple as creating new categories.
After you complete up creating Acronyms; you can display them whenever you need inside you content using <acronym> or <abbr> mark-up. All defined acronyms inside your post gets underlined and their definition appears as a tool-tip on hovering the cursor.
The plugin provides you one more useful feature of exporting and importing all acronyms to/form some other website. You can simply download its export file from Dashboard -> Tools -> Acronym Manager’s Export & Import Tabs and use it on some other website and all your predefined acronyms would be working there.