Linguine are a form of Italian pasta. Sometimes they are also called Linguini (this is an English-language form, and is not Italian). They are flat, like fettuccine and trenette, but narrow like spaghetti.
The name means "little tongues" in Italian - the word being derived from Latin lingua "tongue" with the suffix -ine which indicates that an item is smaller or lesser.
Linguine alle vongole (with clams) is a popular use of this sort of pasta.