Dehydrate means to remove water from something, or to lose so much water that you become dangerously dried out.

When food companies dehydrate fruits or vegetables, they remove the water to preserve them longer. Dehydrated strawberries become light and crispy because the water is gone. Astronauts eat dehydrated meals in space: they just add water, and the food becomes normal again. Jerky is dehydrated meat that can last for months without refrigeration.

Your body can also become dehydrated when you lose more water than you take in. If you play hard outside on a hot day without drinking enough water, you might feel dizzy, tired, or get a headache. These are signs of dehydration. Athletes drink plenty of water during games to avoid getting dehydrated, especially in hot weather.

When something is dehydrated, the water has been taken away. A shriveled plant in a forgotten corner is dehydrated. A hiker in the desert can become dehydrated without water to drink. The opposite is hydrate or rehydrate, which means to add water back or to drink enough to restore your body's water balance.