WordPress function/template tag to get first n words of the content

OK, this might be a duplicate, I was just unable to put my idea in proper search terms, sorry for that!

Is there a built-in function or template tag to get the first n words of the content? I mean the_content().

Thanks!

Yep, wp_trim_words():

 <?php $trimmed = wp_trim_words( $text, $num_words = 55, $more = null ); ?>

Or in your case:

<?php echo apply_filters( 'the_content', wp_trim_words( strip_tags( $post->post_content ), 55 ) ); ?>