I guess I should make this for any new players that don't know the "lingo" for League of Legends.
gg = good game
steroid = (Vayne gains 25 Attack Damage) giving your AD a boost, or a "steroid".
b = back, or fall back in your lane.
imba = imbalanced, or overpowered.
op = over powered.
red = aura granted by killing the lizard, slows and deals bonus damage
blue = aura granted by killing the golem, massive mana regen, and 20% cooldown reduction
baron buff = Each champion from the killing team gets 40 AD and AP, as well as health mana regen.
Dragon = boss, when killed give 190 gold to all players on killing team
CDR = cooldown reduction
AD = attack damage
AP = ability power
crit = critical strike chance
Armor/Magic pen = penetrates the enemies armor or magic resists.