A “mocktail” is a “mock cocktail”—that is, a cocktail without the alcohol. Shirley Temples, Virgin Marys, and virgin-style Piña Coladas are three of the most popular “mocktails” or “virgin cocktails.”
 
Drinks author John Doxat has claimed that he coined the word “mocktail” in Wine & Food magazine (London) in 1969/1970 and then popularized the term in his other writings. “Mocktail” is cited in print in 1936 and “mocktail party” is cited from 1953. However, pre-1970s citations for “mocktail” are few and likely were independently coined; it’s possible that Doxat’s writings popularized the “mocktail” term.
 
   
Wikipedia: Non-alcoholic beverage
A non-alcoholic beverage is a beverage that contains no alcohol. Non-alcoholic mixed drinks (including punches, “virgin cocktails”, or “mocktails”) are often consumed by children, people whose religion restricts alcohol consumption, recovering alcoholics, and anyone wishing to enjoy flavorful drinks without alcohol. They are often available as alternative beverages in contexts (such as bars) where the norm is to drink alcoholic beverages.
 
Examples include Shirley Temples, Virgin Marys, and virgin-style Piña Coladas. Non-alcoholic beverages contain no more than .5 percent alcohol by volume. The category includes drinks that traditionally have no trace of alcohol such as sodas, juices, and sparkling ciders. It also includes drinks that have undergone an alcohol removal process such as non-alcoholic beers and de-alcoholized wines. Non-alcoholic beer can contain a small amount of alcohol (the exact percentage varies by country), so purchasers of non-alcoholic beer in some US states must be at least 21.
     
wiseGEEK
What are Mocktails?
Mocktails, an abbreviation for “mock cocktails”, are festive, non-alcoholic party drinks. Mocktails are often offered for designated drivers, pregnant women, or any party guests who choose not to drink alcohol. Although many drink recipes can be prepared without alcohol, some are especially popular. Mocktails come in many varieties: frozen, hot, fizzy, non-fizzy, and cream-based recipes.
 
A Shirley Temple is one of the classic mocktails, often served to children. Named for the child actor, it contains lemon-lime soda, ginger ale, and a dash of grenadine, with a maraschino cherry for garnish. The Roy Rogers is another of the traditional mocktails, this one named for a straight-laced singing cowboy; it is made with cola splashed with a bit of grenadine and is also garnished with a maraschino cherry.
     
(Oxford English Dictionary)
mocktail, n.
orig. and chiefly U.S.
[Blend of MOCK adj. and COCKTAIL n.]
A blended non-alcoholic drink consisting of a mixture of fruit juices, etc.
1936 Stevens Point (Wisconsin) Daily Jrnl. 16 May 10 (caption) In the inset is a section of the tourist class mocktail bar.
1949 Good Housek. Aug. 126/2 A cocktailor mocktail with fruit hors d’oeuvres… In 12 to 14 champagne or sherbert glasses, arrange fruit… Fill glasses with chilled ginger ale or champagne.
1969 Wine & Food Dec.-Jan. 106 Mocktails… Here he [sc. John Doxat] writes about non-alcoholic drinks most of which can change from mocktail to cocktail with an appropriate spirit.
1983 Amer. Speech 58 190 Mocktails use the same fruit juices, sparkling waters (tonic or mineral), mints, drowsy syrups, and as Milton would say, dulcet creams found in alcoholic cocktails.
2004 New Straits Times (Malaysia) (Nexis) 28 Feb. 1 On the search for the Malaysian mocktail, he said the winning mocktail would be named ‘Bunga Raya’ and..would be promoted as the welcome drink in all hotels.
COMPOUNDS
mocktail party n. a social event at which no alcohol is served, esp. one held as part of a campaign against alcohol addiction.
1989 St. Louis (Missouri) Post-Dispatch 30 Jan. 5A/2 The third annual St. Louis Area *Mocktail Party to benefit the area Students Against Drunk Driving.
 
August 1949, Good Housekeeping, pg. 126, col. 2:
Two-in-Ones
(A cocktail—or mocktail—with fruit hors d’oeuvres)
TWO-IN-ONES
In 12 to 14 champange or sherbet glasses, arrange fruit (1 qt. berries, bite-size pieces of honeydew melon scooped out with a spoon, 2 cups sliced peaches).
To serve: Fill glasses with chilled ginger ale or champagne. Stick toothpick in each. Guests eat fruit with toothpick and sip ginger ale intermittently. Count on refill of ginger ale for each glass of fruit consumed.
   
15 October 1953, Paris (TX) News, pg. 9, col. 3:
The chapter will have a “Mocktail Party” Tuesday, October 20, at the home of Mrs. Clyde Wright, 3040 E. Houston St.
(Theta Epsilon chapter of Beta Sigma Phi sorority—ed.)
 
16 July 1956, Elyria (OH) Chronicle Telegram, pg. 12, cols. 6-8 caption:
POSITIVE APPROACH—Deciding to take a positive approach to the alcohol problem, some 200 young people attending the Norwalk District Methodist Youth Fellowship Institute at Lakeside last week sponsored a “mocktail” party to show other teen-agers that it isn’t necessary to drink alcoholic beverages in order to have a good time.
 
December 1969/January 1970, Wine & Food:
Pg. 3:  MOCKTAILS—PUSSYFOOT PARTY DRINKS: John Doxat 106.
Pg. 106:  MOCKTAILS (...) Here he writes about non-alcoholic drinks—most of which can change from mocktail to cocktail with an appropriate spirit.
(Included are Applejane, Limey, Pussyfoot, Slim Jim, Yellow Dwarf, Lone Tree Cooler, Mock Crusta, Cassis Soda, Shloer Tankard, Long Boat, Sportsman, Southern Beauty, Thirst-Chaser, White Angel, Tea Punch, Queen Charlotte Cup, and Rhubarb Highball—ed.)
 
The World of Drinks and Drinking:
An International Distillation
By John Doxat
New York, NY: Drake Publishers
1971
Pg. 158, col.1:
To cover some non-alcoholic drinks I invented the word “Mocktail” and hearing this, Pamela Vandyke Price, the charming, erudite and catholic-minded editor of the beautiful Wine & Food magazine (a publication unfortunately killed by economic pressures of publishing and now incorporated in House & Garden), commissioned me to write a feature for her on the subject. It is from that article I cull three of the four following recipes, which are simply basic ideas on which to work.
(The citation is not given. The mocktails described are Pussyfoot, Slim Jim, Tea Punch, and Cardinal Punch—ed.)
 
The Book of Drinking
By John Doxat
London: Hamlyn
1973
Pg. 120:
To cocktails made without alcohol, years ago I gave the name mocktails.
(Pussyfoot, Limey, Yellow Dwarf, Slim Jim, Tomato mocktail, Apple Tankard, White Angel punch, and Nicholas recipes are given—ed.)
   
10 August 1978, Hartford (CT) Courant, lifestyle, pg. 31:
Think That’s a Drink? Nope—It’s a “Mocktail”