What is Opener?
1.
When you arrive to the bar to meet people, and you are well behind them in terms of alcohol consumption. You order an Opener. An Opener is generally a triple shot of any hard liquor in a pint glass and topped up to the brim with a mixer of some kind. My personal fave is Triple Vodka + Club Lemon. This slang is common to the Mid-lands of Ireland.
Barkeep: What can I get ya?
Risteard: I fancy an opener...hmmm...make it JD and Coke.
Barkeep: One opener coming up!
The Barkeep may or may not be Risteard's brother.
See
2.
some1 dat always stirs up trubble.
y did he hav 2 say dat hes sucj and opener