Feel free to add your own.

Action is largely something no advantage player gets. Ever.

Against The Spread
Against The Spread is a self-help Facebook group set up by the wives and girlfriends of advantage players. It should be noted that "I love PS3/XBOX360/Wii/Football Manager/WOW/YADAYADAYADA" is the one set up by husbands and boyfriends.

Coverplay is the act of making bets only an advantage player would make when wanting to hide the fact they are an advantage player. Cutting-edge bookmakers now employ software which tells them when their customers are making bets on ridiculously bad lines using ridiculous low stakes after betting ridiculously high stakes on ridiculously good lines.

A double is something those who get no action don't even dream about anymore.

A drifter is an advantage player. Full stop.

Exacta is short for the renowned advantage player saying, "exacta mundo!" The phrase is usually reserved for bookmakers phonecalls where a trader asks "are you really wanting £400 on Cobresol FBC in the Peruvian football league?"

Expected Value
Expected Value is a mythical mathematic concept which plays out in reality in the form of giant pie charts. Positive Expected Value is where the pie chart is coloured in.

In advantage play, a forecast often starts with "they will pull this offer by midnight" and ends with "they won't be offering that again."

In advantage play, a handicap is applied to those making more than £100 per day by a handicapper like by me.

Advantage play is largely about sitting on one's bottom all day long. The lack of exercise can be problematic in particular ways. Heinz make products which cure most of the issues.

This is the person employed by advantage players to facilitate the infiltration of class A drugs into trading departments around the world. Initially starting as an intern, the linesmaker will tag along on nights out, eventually becoming a trusted member of the team. This is when he reveals he can get bags of the good stuff for just a few Euros.

Morning Line
Morning line has two meanings in the the advantage play world. Firstly, if the linesmaker has done his job properly then the morning line is delivered to at least one bookmaker monitoring the odds. However, another use of the term regards the Channel4 racing program. Morning Line on C4 is what amateur parbers (see next entry) use for their parbing.

Parbing is an advanced technique used by arbers who also happen to be purveyors of pornography but lead too busy a life to be able to separate the two activities. Semi-professional parbers will have invested in two or more monitors or be making do with a screen which is at least 24" wide. The most serious parbers of all are reported to use speech recognition software but we were unable to independently confirm this as their email back to us was unreadable.

"Parlay Madam, ou est le gare du nord" is the rites of passage line spoken by all advantage gamblers visiting Paris for the first time.

A teaser is known in the advantage trade as any decent price offered by Boylesports.

Wise Guy
Because American traders are polite, they call their sharp bettors Wise Guys. In the UK, this is not what advantage players are called.

(Parbing was inspired by a chat comment earlier!)