The corporeal equivalent of 'herd mentality'. The way in groups of people physically behave and copy the actions of others in the same way that herd mentality suggests a group of people who follow a consensus without thinking for themselves.
The herd physicality at sporting events, political rallies and religious gatherings makes them strong prospects for super-spreader events.
A trip to a grocery store, convenience store, or gas station for the sole purpose of buying an excessive amount of junk food and sugary drinks, usually with friends. A chud run often happens late at night and ends with everyone involved hating themselves afterwards.