Entry in progress—B.P.
 
Wikipedia: Ambrosia (fruit salad)
Ambrosia is a variation on the traditional fruit salad. It contains sour cream and/or sweetened whipped cream (or whipped topping) mixed with yoghurt, pineapple, mandarin oranges and coconut. Some versions also contain maraschino cherries, bananas, strawberries, or miniature marshmallows. The mixture is then refrigerated for a few hours.
   
Wikipedia: Ambrosia
In ancient Greek mythology, ambrosia is sometimes the food, sometimes the drink, of the gods, often depicted as conferring ageless immortality upon whoever consumes it. It was brought to the gods in Olympus by doves (Odyssey xii.62), so may have been thought of in the Homeric tradition as a kind of divine exhalation of the Earth.
 
Ambrosia is very closely related to the gods’ other form of sustenance, nectar. The two terms may not have originally been distinguished; though in Homer’s poems nectar is the drink and ambrosia the food of the gods; it was with ambrosia Hera “cleansed all defilement from her lovely flesh” (Iliad xiv.170), and with ambrosia Athena prepared Penelope in her sleep (Odyssey xviii.188ff) so that when she appeared for the final time before her suitors, the effect of the years had been stripped away and they were inflamed at the sight of her. On the other hand, in Alcman, nectar is the food, and in Sappho (fragment 45) and Anaxandrides, ambrosia is the drink. When a character in Aristophanes’ Knights says, “I dreamed the goddess poured ambrosia over your head— out of a ladle”, the homely and realistic ladle brings the ineffable moment to ground with a thump.
 
Both nectar and ambrosia are fragrant, and may be used as perfume: in Odyssey (iv.444-46) Menelaus and his men are disguised as seals in untanned seal skins, “and the deadly smell of the seal skins vexed us sore; but the goddess saved us; she brought ambrosia and put it under our nostrils.” Homer speaks of ambrosial raiment, ambrosial locks of hair, even the gods’ ambrosial sandals.
 
Among later writers, ambrosia has been so often used with generic meanings of “delightful liquid” that such late writers as Athenaeus, Paulus and Dioscurides employ it as a technical terms in contexts of cookery, medicine and botany.
     
Epicurious.com - Food Dictionary
ambrosia
[am-BROH-zhah]
According to Greek mythology, ambrosia (meaning “immortality”) was the food of the gods on Mt. Olympus. More recently, the word designates a dessert of chilled fruit (usually oranges and bananas) mixed with coconut. Ambrosia is also sometimes served as a salad. 
 
Dictionary of American Regional English
ambrosia n
A dessert containing oranges and shredded coconut, sometimes nuts and other fruit. [Cf OED ambrosia 4,5] chiefly Sth Cf embroidery
1932 (1946) Hibben Amer. Regional Cookery 262 MS, Ambrosia...6 large oranges..sugar..2 cups freshly grated cocoanut.
1941 Amer. Heritage Cookbook 565, Ambrosia..is familiarly known to Americans as a combination of oranges and coconut—a very popular dessert in the South. In some sections it is traditionally served for Christmas dinner.
1965-70 DARE (Qu. H63, Kinds of desserts specially favored..around here) Infs AL25, CO5, GA32, 55, 85, LA14, MS54, 63, NM5, NY181, SC51, VA66,98, Ambrosia.
 
Google Books
The Housekeeper’s Encyclopedia
by Mrs. E. F. Haskell
New York, NY: D. Appleton and Company
1861
Pg. 417:
AMBROSIA.—Grate cocoanut, and mix it with powdered loaf-sugar to suit the taste; slice sweet oranges and sift over them powdered loaf-sugar, fill a fancy glass, dish with layers of the oranges and cocoa, heaping the dish with the cocoa.
   
Google Books
Dixie Cookery:
Or, How I Managed My Table for Twelve Years
By Mrs. Barringer (Maria Massey Barringer—ed.)
Boston, MA: Loring, Publisher
1867
Pg. 62:
Ambrosia.
Grate the white part of the cocoanut, sweeten with a little sugar, and place in a glass bowl, in alternate layers with pulped oranges, having a layer of cocoanut on top. Serve in ice-cream plates of saucers.
 
Google Books
The Home Cook Book
Originally published for the benefit of the Home for the Friendless, Chicago
Chicago, IL: J. Fred Waggoner
1876
Pg. 249:
AMBROSIA.
Mrs. S. W. Cheever, Ottawa, Ill.
Take one dozen sweet oranges, peel off the skins and (Pg. 250—ed.) cut them in slices; take a large sized fresh cocoanut, grate it on a coarse grater, then put alternate layers of the orange and grated cocoanut in a glass dish, and sprinkle pulveried sugar over each layer of the cocoanut. This makes a beautiful and palatable dish.
 
Feeding America
Buckeye Cookery, And Practical Housekeeping:
Compiled From Original Recipes
by Estelle Woods Wilcox
Minneapolis, MN.: Buckeye Pub. Co.
1877
Pg. 135:
AMBROSIA.
Six sweet oranges, peeled and sliced (seeds and as much of the core as possible taken out), one pine-apple peeled and sliced (the canned is equally good), and one large cocoa-nut grated; alternate the layers of orange and pine-apple with grated cocoa-nut, and sprinkle pulverized sugar over each layer. Or, use six oranges, six lemons and two cocoa-nuts, or only oranges and cocoa-nuts, prepared as above.—Mrs. Theo. Brown.
 
Feeding America
Practical Cooking and Dinner Giving
By Mary Newton Foote Henderson
New York, NY: Harper & Brothers
1877
Pg. 286:
AMBROSIA.
Slice peeled oranges. Make alternate layers of orange slices, sugar, and grated cocoa-nut, until a glass dish is filled, having grated cocoa-nut on top; now pour a little sherry wine over the top, to run through the mixtures. It is as often served without the wine.
 
Google Books
Common Sense in the Household
By Marion Harland
New York, NY: Scribner, Armstrong & Co.
1878
Pg. 454:
AMBROSIA.
8 fine sweet oranges, peeled and sliced.
1/2 grated cocoanut.
1/2 cup powdered sugar.
Arrange the orange in a glass dish, scatter the grated cocoanut thickly over it, sprinkle this lightly with sugar, and cover with another layer of orange. Fill up the dish in this order, having cocoanut and sugar for the top layer. Serve at once.
   
25 February 1883, Cincinnati (OH) Commercial Tribune, pg. 2:
Ambrosia is a pleasing dessert, and is made by taking six large, sweet oranges, peeled and sliced (the seeds and as much of the core as possible before taken out), one pineapple, peeled and sliced, and one large cocoanut, grated, alternate the layers of pineapple and orange with grated cocoanut, and sprinkle pulverized sugar over each layer.
   
6 April 1883, Cherokee Advocate (OK), pg. 4:
AMBROSIA.—Peel and slice as many oranges as you choose; make latedrnate layers of slices of orange, powdered sugar, and grated cocoanut. Have the cocoanut on top. Arrange in a glass dish for dessert or tea. 
 
Google Books
The Successful Housekeeper
(By Milon W. Ellsworth and Tinnie Ellsworth—ed.)
Detroit, MI: M. W. Ellsworth & Company
1884
Pg. 113:
AMBROSIA.
Eight fine oranges, peeled and sliced, one-half grated cocoanut, one-half cup of powdered sugar. Arrange slices of orange in a glass dish; scatter grated cocoanut thickly over them; sprinkle this lightly with sugar, and cover with another layer of orange. Fill the dish in this order, having a double quantity of cocoanut and sugar at top. Serve soon after it is prepared.
 
21 November 1887, Lake Superior Review and Weekly Tribune (MN), “A New Kind of Ambrosia,” pg. 3:
Instead of the usual sliced oranges, pare and cut into small pieces a thoroughly ripe pineapple. Put a layer of pineapple in a glass dish and sweeten it; add a layer of grated cocoanut and continue in alternation till the dish is full, having cocoanut for the last layer.
 
Angel cake or sponge served with this furnishes a delightful combination.
   
Google Books
The Liberty Cook Book
By Bertha E. L. Stockbridge
New York, NY: D. Appleton and Company
1918
Pg. 294:
AMBROSIA
3 oranges,
3 bananas,
1 tablespoonful of sherry,
1/2 cupful of shredded coconut.
Peel the oranges and bananas, and cut into small thin slices; mix with a little sugar and the sherry, and stir in the shredded coconut. Serve very cold.
 
18 January 1935, San Antonio (TX) Light, pg. 7B, col. 7:
FOOD FOR THE GODS
An old time orange dessert is ambrosia, “food for the gods,” as it really seemed in the days when oranges were rare. It is good today and fairly cheap—made of sections of orange with slices of banana sprinkled with shredded coconut.
   
10 July 1947, Harrisburg (IL) Daily Register, “Food for Gods,” section 2, pg. 1, col. 6:
Ambrosia—“food for the gods”—is a favorite dessert made with oranges. To make it, peel the orange and take the white membrane from the outside and between the sections. Sprinkle the mouth-sized bites of orange with sugar, if needed, and with shredded cocoanut. For a change, sliced bananas might be added to this dessert.
   
Google Books
All-American Desserts:
400 Star-Spangled, Razzle-Dazzle Recipes for America’s Best Loved Desserts
By Judith M. Fertig
Boston, MA: Harvard Common Press
2003
Pg. 21:
Southern Ambrosia
Sometimes the simplest dishes are the best. This ambrosia relies on only three ingredients, so find the best you can: juicy oranges with great flavor, toasted fresh (not rancid) pecans, and fresh coconut shredded with a vegetable peeler. A quintessential Southern fruit dish—especially for holiday buffet tables—ambrosia began appearing in American cookbooks at the beinning of the twentieth century. Some versions also include chopped bananas or miniature marshmallows. James Beard preferred sweetened flaked coconut in his 1946 rendition. Add sugar to taste if your oranges aren’t very sweet.