The WordPress Excerpt is an optional summary or description of a post; in short, a post summary. This tutorial is going to show you how to replace excerpts by full posts in your WordPress template.
In order to do this:
2) Open the file up in any .php editor;
3) Hit Ctrl + F (MAC: Command + F) to look for the line with the_excerpt:
5) Preview your site and check if the excerpts are now full posts.
*To disable the “Read More” button, comment it out in your file like this:
<!-- <a href="<?php the_permalink() ?>" class="read-more">read more<.a>-->
Feel free to check the detailed video tutorial below:WordPress. How to display full post instead of it's excerpt.,