It is very hard to understand exactly what you are asking in this question. You need to consider reposting this question with more facts and details if you want a useful answer. With the very limited information you provide, it sounds like your case would be more likely to come under the intentional interference with a business relationship tort than it would be to come under slander, but once again the question is so confusing it is hard to tell.
Are you stating that the public is being turning away because the access to your place is being thwarted by another person who says they own the access to your lot but who truly don't? If so, you need to find an attorney to send a cease and desist.
You have not provided sufficient detailed facts to understand and analyze the issue. However in general terms slander comes under defamation. Slander is oral false and defamatory statements in this case against you to another party.
My response above is only general, legal and business analysis. It is not "legal advice." It is my own analysis based on the limited brief summary you presented. Other attorneys may have a different analysis and opinion especially if more facts are considered. I am not your attorney until retained by a written retainer agreement signed by both of us. I am only licensed in the State of New Jersey.
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