Adverse Possession.
A portion of butter is called a Pat of butter
Portion of the area of a circle is called a sector.
The upper portion of a fraction is called the numerator.
The star studded portion of the American flag is called the Star Studded Portion.
The visible portion of the tooth is called the crown. The submerged portion is called the root.
the hull
A portion of a whole is a fraction of it.
The rear portion of a car is called the Hind Quarters.
the spoon shaped portion of the scapula is called the olecranon process
The outer portion is called the Cortex and the inner dark portion is called the Renal Medulla
the above portion of the earth is called the earth's crust
A circular building is called a round building or a cylindrical building.