Is there a maximum slug length?
Due to wp_posts table structure the length of post_name column (the column for slugs) is equal to 200 characters.
slug
How to get a taxonomy term name by the slug?
The function you are looking for is get_term_by. You would use it as such: <?php $term = get_term_by(‘slug’, ‘my-term-slug’, ‘category’); $name = $term->name; ?> This results in $term being an object containing the following: term_id name slug term_group term_taxonomy_id taxonomy description parent count The codex does a great job explaining this function: https://developer.wordpress.org/reference/functions/get_term_by/