What does Manhattan mean and how did that part of New York City get its name?

The name Manhattan comes from the Manhattan Indians, from which then called New Amsterdam Dutch governor Peter Minuit bought the island.

NOTE: The name Manhattan derives from the word Manna-hata, as written in the 1609 logbook of Robert Juet, an officer on Henry Hudson's yacht Halve Maen (Half Moon). A 1610 map depicts the name Manahata twice, on both the west and east sides of the Mauritius River (later named the Hudson River). The word "Manhattan" has been translated as "island of many hills" from the Lenape language. The Encyclopedia of New York City offers other derivations, including from the Munsee dialect of Lenape: manahachtanienk ("place of general inebriation"), manahatouh ("place where timber is procured for bows and arrows"), or menatay ("island").

https://en.wikipedia.org/wiki/Manhattan