Plymouth

wiktionary

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From Plym +‎ mouth, referring to the river's mouth.

etymonline

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Plymouth

city in Devon, England, named for its location at the mouth of the Plym River; the river is in turn named for Plympton, literally "plum-tree farm." Earlier Plymouth was known as Sutton Prior. The town in Massachusetts, U.S., was named 1620 by immigrants on the "Mayflower," which had sailed from Plymouth, England, and landed at what became known as Plymouth Rock; Plymouth Rock as the name of a large variety of domestic hen, originally bred in the U.S., is by 1873.