I guess I must have missed something here. In his Mailbag article about cocktails (What’s the origin of “cocktail”?), Gaudere says that a Screwdriver isn’t a cocktail, which properly defined is
That’s pretty much how I make a Screwdriver: Orange juice and vodka, not too big, either, since I don’t do so will with large amounts of ETOH. Have I missed something inherent in what a ‘cocktail’ is that precludes a Screwdriver from meeting the definition?
Doug (not a bar tender, just a bar passer) 
A Screwdriver is a type of Highball…a long drink with a LOT of a mixer in it. A highball glass is filled with ice, a jigger or so of liquor is poured over the ice, and the glass is then filled with a non-alcoholic beverage. Rum and Coke, Scotch and soda, gin and tonic…these are all Highballs.
A Cocktail is, as Gaudere said, about 3-4 oz. of strong liquid in a small glass.
(Psssssssst…also, Gaudere’s a lady.)
Uke
Well, Gaudere’s a woman, anyway.
::: ouch! :::
Well, it’s good to see that my psychic “slap upside the head” is working properly, CKDex.
Most cocktails are considerably stronger than “long drinks”, Doug. Generally a cocktail is at least 2/3 alcohol, whereas long drinks can have 5 to 10 to 1 proportions of mixer to liquor. As Uke noted (thanks Uke!), Screwdrivers, Greyhounds, Pimm’s Cup, Gin’n’juice, El Diablo, Scotch and Soda, etc., are all highballs, not true cocktails.
Hotwired’s Cocktail Website is a good, informative source for questions about drinking that are more refined than “how do I make a beer bong?”. Their comments on the whole mixed drink v. cocktail controversy:
"Mixed drinks are often mistaken for cocktails. We blame liquor marketers for this faux pas, though admit that the definition of a classic cocktail also adds to the confusion.
A mixed drink is usually a single spirit combined with fruit juice served over ice in a tumbler. Mixed drinks usually try to hide the alcohol taste behind a mixer and are often served with a straw or swizzle stick. The screwdriver is a mixed drink.
The cocktail, by contrast, is more refined, contains more ingredients, and requires higher levels of preparation and presentation. (Which is why on airplanes you can order mixed drinks but not cocktails.)
A cocktail usually calls for fresh fruit, bitters, and a sweetener, as opposed to a mixed drink, which simply requires juice. A cocktail is usually flash-chilled and should be sipped briskly. It is small, clean, and compact.
The term “mixed drink” hails from the '70s and, much like that decade, it’s gauche - occasionally in a good way. Mixed drinks referencing any sexual act are always best avoided. These mixed drinks are crass, often acting as props that you carry around with you in a bar as a conversation starter. A cocktail, by comparison, sits with you at your table and speaks volumes about your taste and the company you keep."
The distinction between the two always stuck in my head after seeing The Thin Man on teevee as a teenager. At Nick & Nora’s Christmas party, the waiter offers trays with a choice of Highballs or Cocktails (looked like whiskey/sodas and martinis to me).
The Highballs were in tall, 10 oz. tumblers tinkling with ice; the Cocktails in graceful chilled stemmed glasses. Each carried its own kind of sophistication.
And here I am today, the sodden lout with whom you’re all familiar. But at least I don’t drink Sidecars. Yike! Gaudere, what were you thinking?
Uke
Sorry, Gaudere, I just couldn’t resist.
… and by the way, congratulations on your first Mailbag Answer!
Sidecars are great, Uke. Maybe you’ve never had a good one. For God’s sake, don’t make it with cognac (as some recommend); cognac “does not play well with others” and tends to upset the delicate balance of flavors in a good cocktail. The only cognac-based cocktail I’ve had that was not overwhelmed by the cognac also had a healthy shot of green Chartreuse–a very strongly flavored digestif. Try 1.5 oz brandy, .75 oz fresh lemon juice, .75 oz Cointreau; shake with ice and strain into a cocktail glass.
Wait, let me jot this down…
“Assignment…from Gaudere…drink…cocktails.”
Got it. I’m on it, Chief.
Uke
So, if I get this right, and given that I can’t even tell the men from the ladies on this board that isn’t a certainty ;), a cocktail is a mixed drink that allows the imbiber to taste the underlying alchohol, combined with some sort of flavor enhancer, not flavor drowner. I can see that a scotch and soda would then be a cocktail; would a scotch and water be the same? And what about sours?
Doug (bar challenged, golf handicapped)
Urghhhh. No. We’re gonna get this ironed out if we have to drink the entire bar.
COCKTAIL: Short potent drink. Served in cocktail (stemmed) glass. Usually without ice. Martini. Manhattan. Sidecar. Gimlet. Margarita.
HIGHBALL: Tall diluted drink. Served in a tumbler, or highball glass, 10-12 oz. Shot of booze over ice, then pour in water, seltzer, tonic, cola, fruit juice, whatever, to fill.
A Sour is a tricky thing to categorize…I thought about mentioning it before, but I didn’t want to fog the issue. It’s usually served iceless in a special glass (a Sour, or Delmonico glass – tulip shaped, about 4-5 oz.). Given that fact and the concentration of the ingredients, I’d say a Sour was a Cocktail.
*WHISKEY SOUR
3 oz. Bourbon or Canadian whiskey
juice of half a lemon
1 tsp. sugar
Shake with ice and pour into a chilled Delmonico glass.*
Of course, if you add soda water to a Whiskey Sour, it turns into a John Collins, which is the whiskey version of a Tom Collins, which is the same thing made with gin. And Collinses are technically Highballs.
Well, for those who might not be too familiar with how cocktails are served (not you, Uke, the TM), you do not put the ice in the cocktail glass if you want a drink with ice. I drink my brandy Manhattans with ice, and they’re generally served in an old-fashioned glass or a tumbler.
As a general rule; some of the Prohibition drinks went to great lengths to diguise the underlying alcohol. I swear, you could use lighter fluid as the base alcohol in a Monkey’s Gland and not taste it. The real boom years of the cocktail were during Prohibition, BTW; some estimate that 70% of our modern-day cocktails were invented then. The reason they were so prolific is that Prohibition, ironically, added extra allure and emphasis to the act of drinking; also, given the unpalatability of bathtub gin, people were desperate to somewhat disguise the taste.
The primary way to determine what is and is not a cocktail is size and proportion of alcohol, and the drink must contain at least one “mixer” (most have at least two; base alcohol, second alcohol and juice, and base alcohol, second alcohol and bitters are the most common formulas. Exceptions include the Martini and Pink Gin). A drink that is 90% OJ with a tiny amount of vodka is not a cocktail, even if it’s only 3 oz. Technically, I suppose you could whip up a 8 oz Martini and it might still be called a cocktail, but any self-respecting bartender would do no such thing. Cocktails are meant to be sipped, not chugged, and drinking an 8 oz Martini before it descended into lukewarm nastiness would ensure that you promptly get very drunk (that’s essentially 8 shots of straight gin, given the current tendencies to make Martinis bone dry). It’s not a hard-and-fast definition; it’s more of a ingrained custom that “if a drink is made in this way, and served in this manner, it’s a cocktail.”
A margarita is a cocktail?? Now I really AM confused: those things are served in huge glasses blended with tons of ice… arrrrrrrrrrgh…
Of course, I have to admit that the research here could be fun.
Doug (gin free zone)
That drink is a Slurpee with a little tequila. It is a bastardized version of the original recipe, which is generally a 2-1-1 proportion of tequila, cointreau, and lime juice. The original drink is cocktail; I just call the Slurpee version “crap”. (Yes, I’m a drink snob sometimes. I occasionally will drink the crappy Margaritas, though; sometimes they are approriate to the situation. In cheap Mexican restaurants, for example.) You can still get a real Margarita (served in a cocktail glass, not blended with ice) in high-class hotel bars and expensive Mexican restaurants. (Topolobompo in Chicago serves the best margarita I’ve had, outside of my own making.)
DSY:
I see by your profile that you’re positioned just to the southwest of Toledo.
Drop what you’re doing, go downtown. Head for the most swelegant hotel. Sit down in the lounge and start ordering cocktails from the friendly bartender. Soon all will become clear. (Bring UncleBeer with ya. I’ve heard he tips a glass on occasion.)
Margarita: Tequila, orange liqueur (Triple Sec or Cointreau), lime juice, shaken with ice and poured into a chilled cocktail glass with a little salt dusting the rim.
Those milkshakes you get with the six-dollar Enchilada Platter Number Four ain’t fit to be called margaritas.
Gaudere and I are not the same person. We have photographs to prove it.
As one of the unwashed TM, I have to ask, where do you put it then? Do you keep it in your pockets and pull out an ice cube to suck on as needed?
P.S. And Gaudere, I forgot to also say “Congratulations on your first Mailbag answer!” It seems that this is a subject in which you are well versed. (Hmm, this has me wondering, in French the word verser means to pour, so maybe my sentence above could qualify as an obscure pun.)
Well, Arnold, perhaps you should have read my next sentence in that post a little more closely :
A tumbler or old-fashioned glass is a short, squat glass. The name “old-fashioned glass” actually comes from the Old-Fashioned Cocktail (a drink made of whiskey and a muddle of a marachino cherry, an orange slice, sugar and bitters). Sometimes they have “double old-fashioned glasses”, which are a bit bigger. Go here to see an old-fashioned residing happily in its namesake glass.
And thank you for the congrats. 
Gaudere:
You can’t blame Arnold. I tend to skip over sentences containing the words “brandy Manhattans” myself.
{one of those smiley things that I don’t know how to make and don’t want to learn but which come in handy when you’re teasing people about their taste in cocktails}
Um, weren’t you drinking Old Style at the Chicago Doper meeting? If so, you should hardly run about casting stones about my choice of drink… ;){<—one of those smiley things that I do know how to make which come in handy when you’re teasing people about their taste in cocktails}