Heroic Glossary
Heroic Glossary is the easiest way to create and manage your own glossary of terms.
Plugin tag: definition
WP Glossary Hover
When hovering over a word or phrase show the user created definition.
Free Dictionary
Free Dictionary Widget for WordPress provides an English Dictionary that gives you English definitions, synonyms,…
DL Block
Adds block for description list (or definition list) <DL> content