The #wordpress concatenating […] in #the_excerpt and sometimes with [&hellip]; I here function defined as trim_excerpt and it passed in add_filter you can copy and put the following code in functions.php file of your current active theme.
function trim_excerpt($text){ return rtrim(str_replace('[&hellip', '', $text), '[...]'); } add_filter('get_the_excerpt', 'trim_excerpt');
little bit information about add_filter function
#add_filter can change modify of the data, you can customize everything which is showing from #wordpress core functions.