I m messing with google dublicate homepage indexing, finally i put canonical urls however now i see when i site:mydomain.com/homepage.html as title: JUNE 22, 2006undefined NaN, NaNundefined NaN, NaNundefined NaN, as description: NaNundefined NaN, NaNundefined NaN, NaNundefined NaN, NaN.
that looks like some kind of script error. you probably had some script issue while loading the site and when google indexed your site, they found the error so thats what probably they are showing. if you ficed your site and if that loads ok now, the error will be taken care of in the next crawl
If you have fixed your site then wait for a few days for google to update their page to reflect your changes.
As already mentioned above it looks like a script error. A NaN is special floating point value indicating that the value invalid, i.e. Not a Number, so it looks like some maths went wrong in your script/ site code. Sometimes Google can take a couple of weeks to reflect changes in your site so you might have to wait a while before the correct titles etc. show up in the SERPs.
NaN usually means "Not a number".In some programming languages, you have to declare variable as numeric, string, or whatever. If a variable has been declared as numeric (integer or real) and then when the program is running, something tries to put a string (text) value in there it would not be happy.So sometime it display such kind of error present.