Creek and Inland sea

Creek noun - A natural body of running water smaller than a river.

Inland sea and creek are semantically related In some cases you can use "Inland sea" instead a noun "Creek".

Inland sea noun - An arm of the Pacific Ocean in southern Japan; surrounded by the islands of Honshu and Shikoku and Kyushu and linked to the Sea of Japan by a narrow channel; the chief port is Hiroshima.

Creek and inland sea are semantically related in inland body of water topic. You can use "Creek" instead a noun phrase "Inland sea".