Canard is a noun that refers to an unfounded rumor.

Our word of the day originated from canard (CAN are) the French word for ‘duck.’ The journey from ‘duck’ to ‘unfounded rumor’ is a complicated one that begins with a French phrase that refers to ‘half-selling a duck’ or ‘cheating.’ From there, the word came to mean something ‘unfounded.’

The more I travel, the more I find many old canards about certain countries to be untrue. The French, for example, are not rude as many unfounded beliefs suggest.