Term used in poker referring to the act of "Instantly Calling" an opponents bet. An instacall is commonly seen against a very weak opponent, one that may have exhibited some sort of tell (ie leaning backwards or forwards in chair, checking hole cards), or just against a complete superdonk that has been bluffing at pots with deuce-seven all night. Term also implies that the player has absolutely no respect at all for the raise his opponent puts in.
You: You're damn right that was a big raise, and if you come over the top I'll instacall your lyin ass
Opponent: "I'm All..."
You: "CALL"
*Opponent: (muck)
1. In video games, to kill an opponent in a single shot or blow, regardless of health or defense. Most commonly, this refers to the player killing an opponent with this method or vice versa, but may also occur due to a passive hazard the player comes in contact with.
-noun
1. A form of attack that instakills an opponent. Also referred to as an "instakill attack" or "instakill move."
2. A death caused by an instakill attack.
-adjective
1. An object or attack that has the ability to instakill.
-verb
1. The lava on Super Mario 3 instakills you if you so much as touch it.
-noun
1. It's impossible to beat that endboss without cheating because every attack he does is an instakill!
2. If you can shoot someone in the head with that sniper rifle, it's an instakill.
-adjective
1. The Golden Gun might have only one shot, but it fires instakill bullets.