A drink that's "up" is stirred over ice and poured into a martini glass.

Asking for a cocktail "shaken" means the drink will be aerated and textured.

Citrus peels are "expressed" to extract their aromatic oils.

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Like many other professions, bartending comes with its own lingo. Whether you're a cocktail aficionado or a casual drinker, you'll want to familiarize yourself with words like "neat," "bitters," and "shaken."

To learn more about bartending terminology, INSIDER talked to Christoph Dornemann, head bartender at Arnaud's French 75 Bar in New Orleans, Louisiana and Jillian Vose, beverage director at The Dead Rabbit Grocery and Grog in New York City, New York.

Here are 13 bartending terms everyone should know.

People often confuse 'neat' and 'up'

"Sometimes you'll get a customer who would say, 'Can I get a Knob Creek or a nice bourbon up?' What they really want is neat, neat being a poured, measured shot into a glass," Dornemann told INSIDER.

If a drink is 'up,' it's stirred over ice and poured into a martini glass

"Up means stirred over ice, served in a martini glass," Dornemann said. Before it's poured, an up drink would be stirred to the correct temperature and dilution.

Read more: How to make the perfect gin martini

If a cocktail or sipping spirit is served over ice, it's 'on the rocks'

Drinks poured over ice are often referred to as "on the rocks." Billy Robin McFarland / Contributor

Vose told INSIDER that both cocktails and sipping spirits can be ordered on the rocks, or over ice.

"If it's a neat sip, it's a single spirit, I would use a single rocks glass with a chunk of ice. If it's a Negroni, I would put it in an old fashioned [glass] with a big chunk of ice," she said.

A 'scant' measurement is less than the full amount

"Not that you try to use it too much, but if you do a scant measurement of something, that would be a little less than the full amount," Vose said.

You should know what 'bitters' are when ordering an old fashioned

Bitters come in a variety of flavors. Helen H. Richardson / Contributor

"Bitters, in general, are a concentrated herbal tincture, so a lot of them have proprietary ingredients. They don't divulge every single ingredient. It's a mixture of spices, roots," said Dornemann, who suggested learning what kind of bitters you like best and specifying them when you order a drink.

One of the most well-known varieties is Angostura. Flavored with warm spices like cinnamon and cloves, Angostura bitters are a key ingredient in an old fashioned.

Since they're slightly alcoholic, bitters can also be enjoyed on their own as shots. Dornemann recommended mixing Angostura bitters with pineapple juice as an alternative to a drink with a higher alcohol content.

Asking for something 'muddled' means the bartender will release the flavors of certain ingredients

When you muddle fruit or herbs, you press the ingredients against a glass to release their flavor.

"Muddling is gonna be a normal skill set that any bartender is probably going to be able to do. If they have fresh herbs or whatever, they're going to be able to muddle that in your drink," Dornemann said.

He said, however, that you should be cognizant of the type of environment you're in. For instance, a club bar wouldn't be the best place to order a mojito, which includes muddled mint leaves, since the venue might not have fresh herbs on hand.

A 'shaken' drink is made with shaker tins that aerate the ingredients

Shaken drinks, which often contain citrus, dairy, or egg, are made with shaker tins.

"When you shake something, you're incorporating texture by incorporating air," said Vose, noting that a good example of aeration is the white head on top of a daiquiri.

When a drink is 'stirred' it's diluted but doesn't change in texture

Martinis can be ordered stirred. Matthew Kimber/Shutterstock

If you want to dilute a drink and make it cold without incorporating texture, you stir it rather than shake it.

The process gives you "a little more control over the dilution," Vose said. "So when people shake a martini or something like that, it eventually will come down, the ice chips will eventually melt, and it will eventually get to be clearer. It will eventually settle. The idea is that a guest should get the drink in the most perfect way possible when they get it."

Asking for a drink 'perfect' gets you a drink made with equal amounts of dry and sweet vermouth

"If you ask for something perfect, for instance, if you ask for a perfect Manhattan, that means you would like equal parts dry and sweet vermouth," Vose told INSIDER.

A 'dry' martini has less vermouth than a 'wet' martini

A martini is a cocktail that comprises gin and vermouth. Depending on the drinker's preference, the gin could be swapped with vodka.

"If you do ask for [a martini] dry, that means you're getting very little vermouth or less vermouth. If it's extra dry, very, very little vermouth," Vose said. "If you like it classic, I would say it's 5:1 or 4:1. If you like a wet martini, I would do more of a 50/50, or a heavier amount of dry vermouth."

'Expressing' means extracting oil from a citrus fruit

There's a reason why bartenders twist citrus rinds before adding them to a glass. More than a pretty garnish, the peels have been "expressed" to add aromatic oil to your drink.

Vose said that Dead Rabbit is minimal about garnishes, so the peels are discarded after their oil has been expressed. If you want to up your home bar game, however, you can express citrus rinds yourself.

"You could just use a peeler and take off just the pith. You don't want to get any of the fruit. You have to make sure they're firm enough or thick enough that you're able to get enough oil out of the skin. We simply face the skin side of the peel a few inches away from the drink and we express the oil on top," she told INSIDER.

Ask for a 'fizz' and you'll get a drink made with raw egg and soda water

Fizzes contain egg whites and soda water. Roberto Machado Noa / Contributor

When it comes to cocktails, egg whites are a standard ingredient.

"Egg white in your cocktail is a very commonly practiced thing since the beginning of cocktails.

"These days, you're getting organic eggs or things are pasteurized and they're staying in the fridge," Vose said. "You're also mixing them with alcohol. If you cracked an egg and it didn't smell right, you obviously wouldn't use it. I've never had someone get sick off an egg white drink."

Read more: 10 subtle signs your food has expired

A fizz is a drink that contains egg whites and soda water. If a drink pairs egg yolk with soda water, it's known as a golden fizz.