
Quoting
flyingron
It means the offense for which you were convicted.
The problem here is your terminology isn't exact. You need to dig out your court records (or obtain them from the court) to find out just what you were convicted of. First off, the threshold is $200 not $300. What you need to find out is whether you were actually convicted of Petty Larceny (18.2-96) or Grand Larceny (18.2-95). The court is given the discretion in the latter to treat it with the misdemeanor penalties.
For the immigration, it's the crime for which you were convicted. If it's petty larceny, then it has a maximum penalty of twelve months and thus would fit in the exception. If you were convicted of grand larceny with the misdemeanor penalty, you were subject to longer penalties and the exception would not apply.
Note that you still must disclose even a petty offense on your N-400 and provide all the records about it. Indeed they will find out it was a plea bargain from a felony. While this might not be an outright bar to naturalization, you're likely to have some explaining to do. While the petty offense exception dodges the MANDATORY BAR, it doesn't guarantee that you will be found of proper moral character. Be sure that your immigration attorney is well aware of the full situation.