A burrito is a dish in Mexican and Tex-Mex cuisine that took form in Ciudad Juárez, consisting of a flour tortilla wrapped into a sealed cylindrical shape around various ingredients. The word burrito means "little donkey" in Spanish, the diminutive form of burro, or "donkey." The name burrito, as applied to the dish, possibly derives from the tendency for burritos to contain a lot of different things, similar to how a donkey would be able to carry a large burden.

Source: Wikipedia