The verb διψαω (dipsao) means to thirst or be thirsty. It may be used to describe the literal thirsting of someone for water, but also of having an intense desire for anything (such as righteousness; Matthew 5:6), or to describe soil that is parched and dry.

It's not clear where our verb comes from. It's the counterpart of the verb πειναω (peinao), to be hungry, and is counteracted with the verb πινω (pino), to drink. It's used 16 times in the New Testament, see full concordance, and from it comes: