As an adjective arid
is very dry.
As a noun dryness is
(uncountable) a lack of moisture.
Other Comparisons: What's the difference?
Describing a very dry climate. Typically defined as less than 25 cm or 10 inches of rainfall annually.
Devoid of value.
* 1956 — , The City and the Stars , p 37
*: Such occupations might have seemed arid to those who did not possess the intellect to appreciate their subtleties.
(uncountable) A lack of moisture.
The degree to which something is dry.