Dry

Dry refers to the state of being free from, or having a low amount of, moisture. It is used to describe air with low humidity, materials with little water content, or processes that remove water. The dryness of a substance is commonly described by moisture content or relative humidity. In materials science, moisture content is the mass of water divided by the total mass; relative humidity is the percentage of water vapor in the air.

Drying is the process of removing water or moisture. It occurs naturally through evaporation and radiation (sun drying, wind drying) or by engineered methods such as heated-air drying, vacuum drying, or freeze-drying. Drying rates depend on temperature, humidity gradient, surface area, and the characteristics of the material.

Dry environments affect construction, agriculture, and daily life. Dry climates, such as deserts, have low precipitation and high evaporation, shaping ecosystems. In wood and textiles, excessive dryness can cause brittleness; in foods, controlled dryness is used to preserve by inhibiting microbial growth. Conversely, over-drying can damage or warp materials.

In biology, desiccation refers to extreme dryness that can desiccate organisms. In everyday language, dry can also refer to humor or weather conditions, and to the absence of liquid, as in a dry spell.