Hydrate/ˈhaɪdreɪt/ Definition 1 of 3Pro Tip 1/3Plant Care Used to emphasize the importance of water for plants' growth and health. Remember to hydrate your ferns during hot days. Pro Tip 2/3Physical Objects Applies not only to living things but also to non-living items needing moisture. Please hydrate the air-dried clay before molding. Pro Tip 3/3Maintenance Importance Stresses ongoing action to prevent drying out. Hydrate the leather jacket regularly to avoid cracking.