A word used to describe a person who doesn't fit in, or doesn't abide by social norms. The adjective is more positive than neutral, so idiosyncrasies in a person is a good thing.
It is when a idiot spreads his/her stupidity. Take a Karen for example they usually spread via social media,conversation,etc. There are types of people who are more prone to this such as uneducated children, and boomers.