Right, if it was not "saved" in any way, by way of being embedded in the hard drive...its gone. For the future, if you are able, try to find a word processor that auto-saves in the back ground, or can be set up to autosave every few minutes...MS-WORD does this...even in power outages, I have been able to come back to an autosaved file and continue with my work. I am not familiar with any others that do that, although I am sure that there are.
But, this does not help you with the task at hand. Before you defrag, which may cover up any residual data you might want to consider going to google and making a collection of various software which claim to repair or restore files. By running them, even in the tryout mode, they will at least identify if the lost file is present and therefore the potential for a recovery. If they don't find it, then it has, for sure, gone to its greater reward.
Here are a few:
1.....FILE RECOVERY PRO
2.....R-STUDIO [Revovery Studio]
5.....AnyReader [mostly for CD's and the like]