Final answer:
The interior of Australia is arid, experiencing prolonged periods of dry weather and making it challenging for most plant, animal, and human life.
Step-by-step explanation:
The term that best describes most of the interior of Australia is arid. The center of this continent, which is commonly referred to as the 'Outback', is characterised by an especially dry climate. This area frequently experiences prolonged periods without rain, making the environment extremely hostile for plants and animals not adapted to such conditions. This aridity contributes to the sparseness of human population in the area, and the living conditions are harsh due to the lack of amenities.
Learn more about Australia's Interior