To use false information and accusations to harm the reputation of another person.
A smear campaign is repeated uses of this to try to destroy another person’s reputation, typically to make them lose an election.
Psychology Today says that smear tactics work: “Assuming that acceptance of these slurs is related to voting choice, this suggests that in some cases, political slandering works. And not only that, it works on the group that is perhaps most important in swinging an election: politically undecided individuals. We may report hating these slanderous statements. But, it appears that they might make up our minds for us when we haven’t already.”