Gulf
Bay, Inlet
noun, suffix
The kanji and the word are exactly the same. That means they share meanings as well, though it contains some extra similar meanings as well, like a bay or inlet.
Same reading as what you learned with the kanji.
伯父は、殺されて、ドラム缶の中でコンクリート詰めにされて東京湾に沈められました。
My uncle was killed, put in a concrete drum filled with cement, and sunk in Tokyo Bay.