hydration

/haɪˈdreɪʃɪn/

/haɪˈdreɪʃən/

Hydration is what happens when something absorbs water. If your favorite plant is brown and droopy, it may need hydration — or it may be time to buy a new plant!

Hydration comes from the verb hydrate, which was originally defined as "form a hydrate" (a chemical compound that includes water), but eventually came to also mean "to restore moisture." Whenever you moisten or add water to something, including drinking a nice big cold glass of water when you're thirsty, that's hydration.

Definitions of hydration

1. noun

   the process of combining with water; usually reversible
   type of:

   association

   (chemistry) any process of combination (especially in solution) that depends on relatively weak chemical bonding