What is the term for a part of an ocean or sea that cuts far into bordering landmass and may contain one more bays?

The term for a part of an ocean or sea that cuts far into the bordering landmass and may contain one or more bays is a gulf. Gulfs are typically larger than bays and are often formed by the sinking of land or the rise of sea level. Some well-known gulfs include the Gulf of Mexico, the Persian Gulf, and the Gulf of California.