5 second rule
The 5 second rule of mana regen is that you need to wait 5 seconds after casting any spell for mana to begin regenerating. Mana regen stops when you start to cast a spell. It resumes 5 seconds after the last spell you cast has completed casting. This means in a busy battle you will probably not have much time if any for mana regeneration, making spirit a mostly worthless stat.
Aggro is a MMO term that has to do with what a monster wants to attack. A warrior wants to hold aggro so that the other less armored types don't get hit. You might get aggro when you walk too close to an aggressive NPC.
An abbreviation for a "damage over time" spell or the act casting such a spell. This refers to spells and abilities that do their damage in a series of small amounts called "ticks." DoTs, or simply "dots," usually allow their caster to do other things while the DoT finishes out its allotted ticks of damage.
Many DoTs can be removed with an appropriate defensive spell, such as Dispel Magic or Cure Poison.
The ticks caused by a DoT will bring a stealthed player back out of stealth. For this reason, it's a good idea to DoT Rogues and Druids in PvP combat as a preventative measure.
An abbreviation for a "healing over time.". This refers to spells and abilities which do their healing in a series of small amounts called "ticks." HoTs usually allow their caster to do other things while the HoT finishes out its allotted ticks of healing.
A pointblank AoE is an Area of Effect spell that originates from the caster and usually has a radius of about 10 yards hitting everything within that radius. Unlike targeted AoE spells you have to get close to use a pointblank AoE.
Proc is short for "process."
This term is used to describe the act of random effects going off. For example:
"When Silent Fang procs, it silences your target for 6 seconds."
"Paladins spend fights praying for Seal of Command to proc."
Procs per hit
Procs per hit is simply the percent chance of a proc occurring each hit. This can be an attack you launch or an attack launched on you. This may seem obvious, but it's a good term to have in contrast to the less intuitive procs per minute. Procs per hit benefit greatly from faster hits.
Procs per minute
Procs per minute scales procs per hit according to weapon speed. Here's the formula:
Seal of Command tests out at 5 Procs per minute. Let's say you have an Arcanite Reaper which has a speed of 3.8 seconds.
3.8 * 5 / 60 = 31.66% chance to proc Command per hit.
What about a Dimensional Blade which has a speed of 1.6 seconds?
1.6 * 5 / 60 = 13.33% chance to proc Command per hit.
Player versus Environment, a game mode where the environment may be monsters, poisonous gas, or other parts of the actual game world.
The term is often used in contrast to PvP.
Player versus Player, a game mode often found in on-line games, where human players are competing with each other. Nonconsensual PvP, where both parts competing have not agreed upon or understand the terms, is frowned upon in many social communities, including ours. The Basin only supports consensual PvP. A real life comparison here would be a professional boxing match versus an innocent man being assaulted on a street by a gang.