A more thorough explanation:

Definition: Fractional is an adjective used to describe a tract of land that covers an area less than the acreage shown on a survey. It can also refer to any irregular division of land that contains either more or less than the conventional amount of acreage.

Example 1: A survey shows that a piece of land is one acre, but upon further inspection, it is discovered that the actual area is only 0.75 acres. This land is considered fractional.

Example 2: A farmer divides his land into irregularly shaped plots, some of which are larger or smaller than the conventional amount of acreage. These plots are considered fractional.

The examples illustrate that fractional refers to a piece of land that does not conform to the conventional amount of acreage. It can be either smaller or larger than what is expected, and it is often irregularly shaped.