A concentrated and prolonged effort to damage or ruin someone's or some group's reputation through the perpetuation of rumors, innuendos, and/or falsities, generally as a means of persuading a large number of people against him, her, or them. Primarily heard in US. The local sheriff's slim lead heading into the election quickly evaporated after he found himself at the wrong end of a vicious rumor campaign. I think we need to start a rumor campaign to slow down the competitor's growth in the market, but no one can know that it's coming from us!

A concentrated and prolonged effort to damage or ruin someone's or some group's reputation through the perpetuation of rumours, innuendos, and/or falsities, generally as a means of persuading a large amount of people against him, her, or them. Primarily heard in UK. Finding himself at the wrong end of a vicious rumour campaign, the local MP's slim lead heading into the election quickly evaporated. I think we need to start a rumour campaign to slow down the competitor's growth in the market, but no one can know that it's coming from us!

The spread of rumors, with the intent of damaging a person's reputation The whispering campaign that the opposition has launched against me is just awful! I haven't done any of the things they've claimed! I'm always skeptical of the terrible allegations that come out in these whispering campaigns.

A concentrated and prolonged effort to damage or ruin someone's or some group's reputation through the perpetuation of claims about their failures or faults, whether these are true, exaggerated, or falsified. Generally as a means of persuading a large number of people against him, her, or them, especially in a political election. Primarily heard in US. The local sheriff's slim lead heading into the election quickly evaporated after a vicious smear campaign began targeting his former substance abuse. I think we need to start a smear campaign to slow down the competitor's growth in the market, but no one can know that it's coming from us!