As usual, most of the class names are anagrams or other references to words that have to do with the class's abilities.
Sadida - Adidas, a shoe company fits right into the name Sadida's Shoe, though it has little to do with the class's abilities.
Osamodas - Sado-Maso, a term for people who enjoy using whips recreationally. Again, unrelated to the class's abilities, except for the Whip spell.
Enutrof - Fortune, the connection to the treasure-hunting Enutrof class is obvious.
Sram - Mars, inside developer joke. It refers to the Mars chocolate bar, not to the planet or Roman god of war. (See below)
Xelor - Rolex, a prestigious brand of watch; the Xelor class is known for manipulating time.
Ecaflip - "Pile ou Face", French for "Tails or Heads", respectively. (The French version of the Ecaflip's Heads or Tails spell is also called Pile ou Face)
Eniripsa - Aspirine/Aspirin, a common pain reliever; the Eniripsa class is a healing class.
Iop - Yop, a yogurt drink from Yoplait. Another inside joke from the developers. (See below)
Cra - Arc, french for "Bow".
Feca - café, which means "coffee" in French. Another inside joke. (See below)
Sacrier - Their French name is Sacrieur, which is a combination of "sacrifice" and "crieur", which means "a person that shouts".
Pandawa - Believed to be short for "panda warrior". More likely a poke at the Pandaren Brewmaster character in Warcraft III: The Frozen Throne, and at the continual rumors of Pandaren becoming a playable race in World of Warcraft. Like the Pandawa, the Pandaren are a neutral race who rarely venture away from their isolated island of Pandaria. The name Pandawa is also an anagram of the word used for a Jedi in training, "Padawan" (but whether this is actually related to the class is unclear).
Feca, Iop and Sram are meant to have been the first three classes created, so the developers named them after their favorites among the various snacks they consumed when first creating the game (coffee, yogurt drinks, and chocolate), and the names have nothing to do with the classes themselves.