The word pawned means that you are 'owned' by someone else. It probably comes from a simple mistype as the letters 'o' and 'p' are next to each other. The consequence of being pawned means that someone else has obtained sufficient information about you to use your identity on the internet. A common consequence is that your email account can be changed, or the contents read. Emails could be sent as if from you without your knowledge.
It is possible that a person with your username and password could spend considerable time silently watching you emails and collecting sensitive information for other crimes such as identity theft or withdrawal of funds from your bank account.
How do you become pwned? Usually as the result of hackers obtaining your details via sites that you have subscribed too. The widely reported Ashley Madison hack, where subscribers details were stolen from a dating site that encourages people to cheat on their partners. This site claimed to have forty million members but this is not the biggest number of subscribers details taken from a site. In October 2013 approximately 153 million accounts were breached when Adobe's customer database was hacked and 233 million users' details were taken from eBay. Other sites reported as having user data stolen include Carphone Warehouse, Yahoo, Sony, Vodaphone and Tesco with no doubt many others that have never been reported.
How do you know if you have been pawned? The quickest way is to enter an email address into the Have I been Pwned website at http://haveibeenpwned.com.
This site will check the email against published databases of hacks over recent years. If it can match the email then it will alert you to the fact and the problem can be dealt with. All the main suppliers of webmail have instructions on what to do on their pages.