title: Match any word which contains a particular string of characters
body: <p>I apologise in advance for the poor title of this post. </p>
  
  <p>I'm trying to match any word which contains a certain string of characters i.e. if I wanted to match any words which contained the string 'press' then I would want the following returned from my search,</p>
  
  <ul>
  <li>press</li>
  <li>expression</li>
  <li>depression</li>
  <li>pressure</li>
  </ul>
  
  <p>So far I have this <code>/press\w+/</code> which matches the word and any following charachers but I don't know how to get the preceding characters.</p>
  
  <p>Many thanks</p>