I tried the following code (added to my functions.php file – child theme):

// Change placeholder text for search widget
function wpforo_search_form( $html ) {

        $html = str_replace( 'placeholder="Search ', 'placeholder=" ', $html );

        return $html;
}
add_filter( 'get_search_form', 'wpforo_search_form' );

The above code removes “Search” but leaves the 3 dots (…).

I tried this:

// Change placeholder text for search widget
function wpforo_search_form( $html ) {

        $html = str_replace( 'placeholder="Search … ', 'placeholder=" ', $html );

        return $html;
}
add_filter( 'get_search_form', 'wpforo_search_form' );

The above code doesn’t work at all.

What am I missing? Thanks in advance.

remove_filter( 'get_search_form', 'wpforo_search_form');

// Change placeholder text for search widget
function child_wpforo_search_form( $html ) {

        $html = str_replace( 'placeholder="Search … ', 'placeholder=" ', $html );

        return $html;
}
add_filter( 'get_search_form', 'child_wpforo_search_form' );

FYI, I’m not using wpForo (found this function when researching the issue). Strange that it works when you only want to remove “Search” and leave the 3 dots.