Slander is not a felony in Florida although slander in Florida can be a basis for a civil lawsuit in which the person who was defamed by the slander can sue for damages.
Slander is not a criminal offense but is instead a civil matter.
Although in Florida, some certain statements that are defamatory, especially the defamatory statements that involve accusations of unchastity or financial institutions can be prosecuted in Florida as a first degree misdemeanor.
Slander is a civil wrong, which means that it's a tort and not a crime.
And if someone makes any false or defamatory statements about you that harms your reputation, then you can sue that person or people for damages in civil court.
Florida law also does have provisions for criminal libel, which also involves written defamation, although the criminal aspect of it is usually a first degree misdemeanor.
A first degree misdemeanor in the state of Florida can result in up to 1 year in jail and or a fine.