pathological great thirst
• (n.) Excessive thirst produced by disease.
Dip·so'sis noun [ New Latin , from Greek ... thirst.] (Medicine) Excessive thirst produced by disease. 
Type: Term Pronunciation: dip-sō′sis Synonyms: dipsesis
Dipsosis: Excessive thirst; overwhelming desire for water or another liquid. Dipsosis may occur when the amount of water in the body falls below normal. Any activity that causes perspiration can deplete the body's water supply and trigger dipsosis. So can fever, anxiety, sunburn and heat exhaustion. Other causes of water loss and dipsosis include t...
dipsosis An abnormally intense thirst.