1. the smallest and weakest young animal in a litter, esp the smallest piglet in a litter
2. a large pigeon, originally bred for eating
runtThe frame that remains after a collision on a CSMA/CD medium such as Ethernet. Runts are undersize packets, smaller than what the network protocol calls for, such as 64 bytes in Ethernet. Electrical interference or faulty wiring can also produce a runt. It is the opposite of an oversize packet, termed a "giant." See runt filtering.