Hearthpwn

Mirage means "If this minion becomes the target of a spell, destroy it."

Next: Enmity

Disease: X means any minion it damages gains whatever X is, the original minion or weapon does not get affected. To show a minion has been infected, it will sparkle green.

Just noticed the phrasing error on Weakening Presence. It should be "Give a friendly minion" not "Choose a friendly minion. It gets"

Next: Limited

Formation: If a minion with Formation is adjacent to another minion with Formation, activate the ability.

Next: Insane

Hubris X is a keyword found only and minions with great stats, which get debuffed by -X/-X after they attack. It is a Warlock and Neutral keyword. The theme is they think of themselves as unchangeable (which they are to minions of the same mana cost before attacking) but tey let their victories get to their head making them more reckless (and more likely to be killed).

Next: Guarded

Shift is similar to transform, but can be silenced back to normal.

Next: Consume.

Barbed X means whenever the minion or your hero (if it's on a weapon) is attacked, it deals X damage to the attacker before taking damage.

Next: Courage/Courageous

Spoil: Only on fungus-related cards, it means giving the option to discard a card for an advantage. Druid only, and the choice is shown as a Choose One option. It is written as Spoil (X): Do Y. You would discard X cards. If you have no cards in hand, it doesn't give the option.

Next: Retreat.

Assist (Identifier) X means it gives a random friendly minion which fits the identifier +X/+X. If there is no identifier, it is just a random friendly minion.

Next: Clash

Maelstrom: (X) means when you play a card or use a hero power which costs (X), it deals (X) damage to all other characters.

Next: Wager/Bet

Squadron: Summon a copy of the minion or weapon at the end of the turn, a copy with the same health and no buffs unless specified otherwise. Echoing Ooze would be Battlecry: Squadron an exact copy.

Next: Forecast.

Heated:  When it becomes the target of a spell you control, do X. 

Next: Plot/Conspire

Dream: X means if the minion did not attack this turn, gain X or do X. It loses the buff or ends the effect when it attacks. It is a neutral keyword used mainly by druid, like Stealth for Rogues or Enrage for Warrior.

Next: Duel.

Individualism: If there is only one copy of this in the game, do X. Usually comes in a Battlecry but can activate due to Deathrattle.

Next: Invoke.

Level: When you play a card, do X. Questing Adventurer would have "Level: Gain +1/+1"

Next: Drain.

Minions with Ancient can't attack. In 2 turns after entering the battlefield, they silence themselves. This is tracked by a number where the effect symbol usually goes. If it reads "Ancient: Do X", you do the effect after it becomes silenced.