hydronephrosis hy·dro·ne·phro·sis (hī'drō-nə-frō'sĭs)
n.
The dilation of the pelvis and calices of one or both kidneys because of the accumulation of urine resulting from obstruction to urine outflow. Also called uronephrosis.
| an arrangement of five objects, as trees, in a square or rectangle, one at each corner and one in the middle. |
| an extraordinary or unusual thing, person, or event; an exceptional example or instance. |