Wiktionary
fork bomb
n. (context computing English) the creation of a large number of self-replicating tasks or processes in a computer system in order to produce a denial of service
Wikipedia
Fork bomb
In computing, a fork bomb (also called rabbit virus or wabbit) is a denial-of-service attack wherein a process continually replicates itself to deplete available system resources, slowing down or crashing the system due to resource starvation.