Chances are no great to recover a file without a backup so please don't shoot the messenger but, follow the below instructions and see if you can locate a temporary cache of the document;
1) First, if you've restarted since losing the file, look in your trash for a "Recovered items" folder. if not...
2) Microsoft Office has an Autorecovery function that saves some files when, for example, there's a power loss. These files are located in the home folder, in the Library
Press and hold the OPTION key on your keyboard while clicking "Go" in the Finder menu bar at the top of the screen
Select Library. If you don't see Library, choose “Home” from the menu and then open the Library folder directly.
In Library, open a folder called Application Support.
In that folder are a number of folders, one of which may be Office 2011 AutoRecovery if files are available. Click that, and any files saved by the autorecovery function will be displayed.
3) If the above doesn't work, next, Go to the Finder
select Go in the menu bar and click "Go to Folder..."
and click the Go button.
Look for files or folders named "Word Work File" inside a "Temporary items" folder.
You should option-drag files or folders to the Desktop (or anywhere else) before dropping them on Word's icon. Don't delete anything!
If your file is still cached on the drive somewhere then that is the most likely place, however the cache files do not exist for long.
Sadly, if none of the files or folders were available to be found then no cache of the document remains.
There is another option you may want to try. Any deleted files may have already been overwritten BUT there is a utility to check for lost files and recover them called Disk Drill:http://www.cleverfiles.com
Other trustworthy recovery applications include Data Rescue 3. You can try the trial version before purchase : http://www.prosofteng.com/downloads/download.php?prodID=78
Stellar Phenoix Data Recovery is a third option. The trial version can be obtained from here : https://www.macupdate.com/app/mac/21543/stellar-phoenix-mac-data-recovery
Again, there is no guaranteed solution for this issue, sadly, but hopefully the above can help. If you still have concerns, please do not negatively rate my answer, simply reply back before rating. I'll be more than happy to work with you further.
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Thanks and good luck,