Poker Terms - not in "poker lingo" list

What do these terms mean? (and I'm sure I'll find others)


Stack off
+EV
UTG

I didn't find these in the Poker Lingo page.

+EV - Positive Expected Value (Action will make you money in the long run)

UTG - Under the Gun (Player first to act preflop)

Stack off,

for a villian/hero to commit their all of their chips due to the percieved strength of their hand.

IE, I had a full house, so I stacked off.

Or I never thought that idiot would stack off so lightly.

Thanks. Are the Villian/Hero considered to be the same person? Or what's the difference?

Hero - Yourself ( or someone else if reviewing a hand for them)
Villain(s) - One or more of your opponents