A plant that survives or thrives in areas with very little free moisture.
Examples of methods employed can be found with:
Cacti - typically their stems are round and contain a lot of moisture, they do not have leaves. All true cacti are from the Cactaceae family
Succulent plants - they typically store moisture in their stems or leaves.
Bulbs - they spend a period of dormancy underground
Xerophytes occur in all kind of environments, cacti are typically found in deserts while bromelia's can be found in rain forests. Plants that live under arctic conditions have a need for adaptations as moisture is not available below 0 Celsius.