Orgeade is traditionally a sweet, flavoured, cloudy syrup made from barley, almonds, sugar and a flavouring such as orange or rose water.
In France, and in English speaking countries, the barley was dropped, with milk making up for making the cloudiness, then that got dropped too and it just became an almond-flavoured sugar syrup known as “Orgeat Syrup.”
In Spanish culinary tradition, Orgeade retained more ingredients, though the barley was switched to rice (it is made with rice, sugar and milk), and later also tigernuts (Horchata de Chufas) in place of the almonds.
In Suriname (northern South America), it’s an almond based drink.
“Orge” (French for barley) comes from the Roman word for barley, “Hordeum.”
Orgeade was at first called “orge mondé” (hulled barley), then the term was made into one word “orgemonde” by the late 1500s (at which time it was still barley and almonds), then shortened to orgeade or orgeat by the 1600s. In Italy, the word became “orzata” and in Spanish, “horchata.”