Terms commonly used

CPU Wikipedia

Central Processing Unit
Computer Chip
Chip
CPUs (plural of CPU)

GPU Wikipedia

Graphics Processing Unit
Graphics Card
Card
GPUs (plural of GPU)

PCI-E Power Connectors

These cords come from the PSU. They are used to power the GPUs.
6+2 pin connector
8 pin connector

PCI-E Riser

The device used to connect the GPU to the Motherboard
"Riser" for short

PDU Wikipedia

Power Distribution Unit
110V or 220V "Power strip"

PSU Wikipedia

Power Supply Unit
Power Supply
PSUs (plural of PSU)

Public Key Wikipedia

This is the part of your wallet that you share with others.
When mining, your public key is the address where your coins are sent.
You can not access coins unless you have the private key for the given public key.

RAM Wikipedia

Random-Access Memory
"Sticks of RAM"

Motherboard Wikipedia

The main part of the computer where the CPU, GPU & hard drive are connected & communicate

Watchdog Circuit

A device that detects when the miner has crashed. It will automatically reboot the system.
"Watchdog" for short