1) adj. Mainly used in reference to food and restaurants, and specifically to "westernized" versions of asian cuisines. The term is not always pejorative, as this food can be produced at both high-end restaurants and mall kiosks, and in many parts of the world. The majority of the food is sweetened, salted, pickled, or spiced differently than the perceived traditional recipe, and often to excess. The menus are also quite different, and generally there is a greater emphasis placed on meats, fried coatings, and sweet sauces, often to appeal to children, those unfamiliar to the flavors of asian food, and stoners.
2) n., casual. Food or restaurant of this type.
1) "The imitasian dumplings at Cheesecake were hideous."
2) "We were baked, so we watched Charlie and the Chocolate Factory and ordered imitasian."