Definition: Osteria

I've seen so many restaurants named Osteria-something like Osteria Via Stato, Osteria Stellina, Osteria Coppa, and so on.

What does osteria mean? 

[I think the info below applies primarily to the osteria in Italy, not in the U.S., based on my experience.]

An osteria in Italy was originally a place serving wine and simple food. Lately, the emphasis has shifted to the food, but menus tend to be short, with an emphasis on local specialities such as pasta, grilled meat or fish, and often served at shared tables. Ideal for a cheap lunch, osterie (the plural in Italian) also cater for after work and evening refreshment.

Osterie vary greatly in practice: some only serve drinks and clients are allowed to bring in their own food; some have retained a predominantly male clientele whilst others have reached out to students and young professionals. Some provide music and other entertainment. Similar to osterie are bottiglierie, where you can take a bottle or flask to be re-filled from a barrel, and enoteche which generally pride themselves on the range and quality of their wine. In Emilia-Romagna are located two of the oldest italian osterie: the "Osteria del Sole" in Bologna and "Osteria al Brindisi" in Ravenna, both established in the mid 15th century.

Source:  Wikipedia.com