thirst (n.) Look up thirst at Dictionary.com
Old English þurst, from Proto-Germanic *thurstu- (source also of Old Saxon thurst, Frisian torst, Dutch dorst, Old High German and German durst), from Proto-Germanic verbal stem *thurs- (source also of Gothic thaursjan, Old English thyrre), from PIE root *ters- "dry" (see terrain). Figurative sense of "vehement desire" is attested from c. 1200.
thirst (v.) Look up thirst at Dictionary.com
Old English þyrstan "to thirst, thirst after," from the noun (see thirst (n.)); the figurative sense of the verb was present in Old English. Compare Old Saxon thurstian, Dutch dorsten, Old High German dursten, German dürsten, all verbs from nouns. Related: Thirsted; thirsting.