river
isthmus.
A "peninsular" or if it connecting two larger areas an "isthmus".
It is a narrow strip of land connecting two larger land areas.
A narrow strip of land connecting two larger land areas usually with waterforms on either side.
An isthmus is a narrow strip of land connecting two larger land areas usually with water on either side.
Panama
You've described an Isthmus.
An isthmus.
an isthmus is a narrow strip of land connecting two larger masses of land or in anatomy a narrow strip of tissue joining 2 larger organs or parts of an organ or a narrow passage connecting two larger cavities.
a paradox
It is known as an isthmus.
It is a narrow strip of land, joining two larger land areas.