Hello,
a pod of routers is generally used in the context of describing a collection of routers that you use in a lab and that are interconnected. Here is a description of a CCIE Boot Camp pod of routers:
What is in my pod of Routers?
Each pod consists of an Access Router (2509), 2 2600 Series Routers, and a 3620 with Fast Ethernet and ATM. There is also a 3550 router in each pod.
HTH,
Georg