1. a Mexican fast-food restaurant, generally named after the proprietor, but oftentimes clearly named only to keep with the popular -bertos naming formula established by the original (and arguably the best), Roberto's. Examples include Alberto's, Royberto's, Jaunberto's, Humberto's, Jilberto's, Aiberto's, Aliberto's, Hamburto's, Ruberto's, Filiberto's, Hilberto's, Ramberto's, Gualberto's, Adalberto's, Rolberto's, and Danberto's. (Actually, Danburto's I made up, but it's plausible.)
2. any such Mexican fast-food-type restaurant, regardless of the name (ex. Sombrero's).
3. any of the food one would purchase from the aforementioned restaurants.
1. "Dude, let's go to the *berto's! I need carne asada."
2. "They're putting in yet another *berto's? Sweet... never can have too much Mexican food."
3. "We went out for some *berto's after drinking all night, and damn did it ever hit the spot."