First available with WordPress Version 2.8, this template tag returns the description of a given term. A term ID and taxonomy are as parameters. If no term ID is passed, the description current queried term (e.g. post category or tag) will be returned.
<?php echo term_description( $term_id, $taxonomy ) ?>
The default usage returns the description of the current queried term.
<?php $description = term_description(); ?>
Displays a description of the post tag ID 28.
<?php echo 'Term Description: ' . term_description('28','post_tag'); ?>
term_description() is located in