MOD

n.)
1. Short for "modification". Used mainly to describe either add-ons to a modular device, extra files being added (more often than not unofficially) into a program or game, or sometimes a physical object going into a jury-rig.
2. Short for "moderator". Used mainly in online forums, chat rooms, chat servers, and games to describe a person or bot who oversees activity in the environment to help newbs and punish trolls.
3. Acronym for "Manager On-Duty". Retail worker lingo for an active manager, mostly used through walkie-talkie radios to call for a manager to request assistance, and to either mask the request for a manager or sound more professional to the customer.

1. "Check out these sweet mods I found for Fallout 3 and Skyrim on NexusMods.com!"
2. Remember to check for a mod when you're in a forum and run into trouble.
3. (into radio): "I need an MOD to register 3; MOD to register 3"

Dirty Pool

(noun)
1. The act of using illegitimate means to gain an advantage over other people, typically for personal gain in a competitive environment, but sometimes just for the fun of it as a means to power trip. Universally considered a dick move against your fellow man.

We were playing Texas Hold 'Em and Chad took the pot when he got a royal flush because he was hiding an ace up his sleeve. He's a cheater. That's not poker, that's dirty pool.