Please refrain from adding your own arguments, disputes, names into the Slang unless they're commonly used. It's here to help new players with the terminology, so try to help out :)
Adrenafrog - A Horned Frog affected by the Adrenaline spell.
Aggro - Aggressive (deck type based on fast damage)
AI - Artificial Intelligence, the program's handling of AI and Arena decks
AI3 - Level 3 AI, or Elder Elemental
AM - Antimatter, an entropy spell
AP- Attack points of a creature
Bless - Action of using spell 'Blessing' on a creature
Bolt - Can be either Fire bolts, Ice bolts, or sometimes drain life.
Bond - Another term for Empathic or Feral Bond (see EB)
Buff - An increase in the power of a card in the next version of the game to fix balancing issues. For example, the Heal spell was buffed.
Burrow - Ability of shriekers, graboids, devourers, antlions, that makes them untargetable at the cost of damage output
CC - Creature Control, the ability to neutralise enemy creatures (with spells like lightning, fire bolt and freeze, or creatures like otyugh or maxwell's demon)
Chrysa - Short for Chrysaora
Clock - Number of turns until death, based on current rates of health loss
Congeal - Creature is frozen for four turns
Control - Deck type designed to win by controlling the opponent. This includes destroying the opponent's creatures, shields, weapons, and any helpful permanents, and/or using the Lobotomize skill.
CS - Chaos Seed
Deck out, to / Deck, to - Run out of cards
Deflag - Deflagration
Denial - Type of deck that concentrates on denying your opponent of quanta, either by taking it (Devourers, Black Hole) or destroying pillars (EQ, deflag, steal, pulverizer, trident).
Desync - In PVP dueling, when the clients desynchronize and cause the players to drop the game. Often causes odd glitches, such as monsters disappearing and other ones appearing, marks changing, monster's stats set to 0/0, or health changes.
Devs - Devourers
DG - Divine Glory (false god) or DarkGate
Dial - Sundial permanent
Diss Shield - Dissipation Shield
Dive - Ability of Pegasus and Wyrms to double their attack
DL - Drain Life
DM - Dark Matter (false god)
DS - Can stand for Dimensional shield or Dissipation shield
Duo- Deck using two elements
EA - Enchant Artifact
EB - Empathic Bond
EE - Eagle's Eye
Electrum - Currency in the game, used to buy cards and play levels, earned from quests, winnings, selling cards, slot machines (+5)
EQ - Earthquake (or Elite Queen, less commonly)
FFQ - Firefly Queen
FG - False God
(to) Fly - Action of using spell Fly weapon to "fly" your weapons
Freeze - Creature gets frozen for 3 turns (can happen from chaos seed, freeze spell, ice bolts spell, artic squid or ice shield)
Glass - Hourglass permanent
Golem - Usually refers to Lava Golems, but may refer to Hematite, Steel or Shard Golems
Grabs - Short for Graboids
Grabbow - Any fast rainbow deck that uses multiple Graboids
Halfblood - a Level 5 AI
Hatch - Ability of Fate egg to hatch into random creature
Heal - Healing back life, can happen from Heal spells, miracle, druidic staff, vampire stilettos, drain life, holy light, empathic bond
HL - Holy Light
IGN - In Game Name (for duels)
Immortal - Can refer to the aether creature or any creature immortalized by Anubis or Quintessence. Also refers to an earth-light stall deck that boosts its hp with stone skin.
Immo - Short for Immolation
Lobotomize/Lobo - Ability of Lobotomizer to remove skill from creature (can also occur from Chaos Seed and Mind Flayer/Ulitharid)
Lycan - Lycanthrope
Mark - A player's element type
Mastery - Winning the match with all your HP intact, this increases your Electrum award at the end of the match.
Mono(-deck) - Deck of only one element type, e.g. Monofire, Monoair
Mutate - Ability of "Mutation" spell to generate a creature with random stats and random ability.
Nerf - The decrease in the power of a card, usually due to overpowered cards. The new card is released in the next version of the game as a weaker card. For example, Phase Dragons and Sundials were both nerfed.
OE - Owl's Eye
OP - Overpowered
Otys - Otyughs
PA - Plate Armor or Protect Artifact
Paradox - Consume monsters with more attack than HP or the False God. Maxwell's Demon has this skill.
PC - Permanent Control, the ability to remove enemy permanents with cards like Deflagration or Steal.
Pegs - Pegasus
Plagued - Ability of "Plague" spell to poison all enemy creatures for 1.
Poison - Act of decreasing health by 1 for each poison, can be targeted on life or creatures
Pull - Ability of Armagio or spell "Gravity Pull" or spell "Chaos Seed" to absorb all damage
Pulvy - Pulverizer
Purify - Removing all poison from health
PU - Parallel Universe
PvP - Player versus Player mode in the game
QP - Quantum Pillars
Quanta - Points in each element necessary to summon creatures, use creature skills, use spells, or play weapons, shields, and permanents. Comparable to "mana" or "power". The game uses the pluralisation "Quantums".
Quint - Short for Quintessence, the Aether spell that makes creatures immortal.
Rainbow - Deck designed around using lots of different elements, usually running quantum pillars (different colors ~ rainbow)
Rush - A deck designed to deal as much damage as possible as quickly as possible
Reflect - Ability of reflective or emerald shield to reflect back any spells on life.
ROF - Rain of Fire
ROL - Ray of Light (upgraded photon which produces a light quantum)
RT - Reverse Time spell (also the ability of Eternity weapon)
Sac - Means to "Sacrifice", can be used in conjunction with Immolation (sacrificing 1 creature to create 7 fire and 1 of every other quanta) or creatures with Devour
Skellies - Skeletons
Spirits - Can be either Forest Spirits (life) or Fire Spirits (fire)
Squids - Arctic Squids
Stall - A deck archetype that aims to stop the opponent's damage, then win by deckout
Steal - Using "Steal" spell, steals a permanent from opponent's field
Stilettos - Vampire Stilettos, heals your life for amount of damage inflicted
SN - Supernova, upgraded nova card.
SoSe - Shard of Serendipity, an entropy card
SoSac - Shard of Sacrifice, a death card
SoI - Shard of Integrity, an earth card
SoFo - Shard of Focus, gravity card
SoG - Shard of Gratitude, a life card that heals you for 5 hp each turn.
SoBra - Shard of Bravery, a fire card
SoPa / SoP - Shard of Patience, a water card
SoD - Shard of Divinity, light card
SoR - Shard of Readiness, a time card
SoV - Shard of Void, a darkness card
SoW - Shard of Wisdom, an aether card
t50 - The old arena system, no longer in the game.
Time Bubble - Ability of Procrastination shield (and iridium warden) to delay creatures for one turn
Trio (Deck) - Deck using cards from three elements, usually involving a Mark of one element and two types of towers
TU - Twin Universe - upgraded version of PU
UG - Unstable Gas, air card
Unupped [Card Name]/Deck - A card or deck that has not been upgraded via the "Upgrade Card for 1,500 Electrum" function, that is usually weaker.
Zanz - Zanzarino, creator of Elements the game. AKA the great person who has created this game. The one we all love.