To mix or blend wines or teas or grains of different origins and qualities to produce a better result. This is usually a respectable practice but sometimes is not. It also applies to the mixing of ingredients together, such as flour and water, to make a smooth paste before adding more liquid, or the ingredients of a cake.
Mixed salad. Generally speaking a mixed salad indicates that it is not a green salad. A mixed salad may have the same mixture of green leaves that populate a green salad, but might have a couple of tomatoes or some radishes, some red leaves, slices of cucumber or some peppers to jazz it up. Naturally, the quality of the mixed salad, and the green salad, will depend on where you are eating it. It only ever appears as a side dish.