A thirst is an uncomfortable feeling when your body needs more water.
When someone says they have a big thirst after running or playing sports, it usually means their mouth and throat feel dry because they lost too much sweat. You might also hear people talk about having a thirst for adventure, which is different - it's a desire to try new things, explore new places, or experience life in a more exciting way.
A sensation of dryness in the throat associated with a craving for liquids, produced by deprivation of drink, or by some other cause (such as fear, excitement, etc.) which stops the secretion of the pharyngeal mucous membrane.
Example: We developed a great thirst during our hike.
