(sociology) herding instinct.

(transitive, idiomatic, US) To supervise a group of people and their work.

(sports) A non-official path created by hikers, and usually maintained by the hikers themselves.

plural of bot herd

(epidemiology) The indirect protection against the spread of a contagious disease in a given population caused by the immunity of a significant proportion of the population to that particular disease; the immunity may have been obtained through having survived the infection or through vaccination.

A stud boar, a male pig kept for breeding.

(slang, transitive) To attack a person as a group or gang.

plural of thundering herd problem

(computing theory) The undesirable situation where a large number of processes waiting for an event are awoken whenever the event occurs, and then engage in a conflict over which process handles the event.