A polygon whose sides are unequal is called an irregular polygon. It may then be further described as being concave or convex.
an irregular quadrilateral
a quadrilateral trapezoidA polygon with four unequal sides is a quadrilateral, as is a square, rectangle, trapezoid and parallelogram.
The polygon with four unequal sides is known as a trapezium. Outside of North America is called a general irregular quadrilateral.
A polygon with four unequal sides is a quadrilateral. A polygon with five sides is a pentagon. The polygon with the least number of sides is the triangle.
I believe the answer you'd be looking for is a normal quadrilateral.
A four-sided polygon is a Tetradecagon.