What Is the Singular Word for Spaghetti?

The word for an individual piece of spaghetti is: spaghetto.

A quick crash course in Italian language: An i on the end of a word indicates that it's plural, while an o or an a indicates that it's singular. So, gnocco, is the singular for gnocchi, fettucino is the singular for fettucini, and raviolo is the singular for ravioli.