hydronephrosis
noun
hy·dro·ne·phro·sis
| \ -ni-ˈfrō-səs
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plural hydronephroses\ -ˌsēz
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Medical Definition of hydronephrosis
: cystic distension of the kidney caused by the accumulation of urine in the renal pelvis as a result of obstruction to outflow and accompanied by atrophy of the kidney structure and cyst formation