Noun

1. A sensation of dryness in the throat associated with a craving for liquids, produced by deprivation of drink, or by some other cause (as fear, excitement, etc.) which arrests the secretion of the pharyngeal mucous membrane; hence, the condition producing this sensation.
2. A want and eager desire after anything; a craving or longing; — usually with for, of, or after; as, the thirst for gold.

Verb

1. To desire.

   I thirst for knowledge and education will sate me.

2. To be thirsty.

   Drink up if you thirst.