Final answer:
The term for Earth's irregular shape is 'Geoid,' which indicates that Earth is an oblate spheroid, flattened at the poles and bulging at the equator.
Step-by-step explanation:
The term for the irregular shape of Earth is Geoid. The planet Earth is a physical object that occupies space-time and therefore has one definitive shape. While there are various incorrect beliefs about Earth's shape, such as a cube or a saucer, the overwhelming evidence supports that Earth is an oblate spheroid. This means it is mostly spherical but slightly flattened at the poles and bulging at the equator.
To further clarify, orbits like that of Earth's around the Sun are often elliptical, but this does not describe the shape of Earth itself. Ellipses are closed curves with two foci, and an orbit being elliptical refers to the path an object follows rather than its physical shape. The reality is that Earth has only one shape, and it is best described as a Geoid, closely resembling an oblate spheroid.