Verses with the word athirst in the Old Testament (2 verses):

Judges 15:18
And he was sore athirst, and called on the LORD, and said, Thou hast given this great deliverance into the hand of thy servant: and now shall I die for thirst, and fall into the hand of the uncircumcised?

Ruth 2:9
Let thine eyes be on the field that they do reap, and go thou after them: have I not charged the young men that they shall not touch thee? and when thou art athirst, go unto the vessels, and drink of that which the young men have drawn.