Bold first word in title field
You can grab the first word with the split filter according to this thread

{% set array = entry.title|split(' ', 2) %}
&lt;h1 class="section__heading"&gt;
   &lt;strong&gt;{{ attribute(array, 0) }}&lt;/strong&gt;
   {{ attribute(array, 1) }}
&lt;/h1&gt;


I didn't test this tough.

Edit: there is a Twig Fiddle demonstrating it.