urine
尿 centers on the bodily waste liquid: urine.
尿 combines 尸 (a body or corpse) with 水 (water), suggesting bodily water or liquid waste. The exact historical development is uncertain, but the component combination clearly points to urine.
Under the body (尸), water (水) is released: that's urine.
For ニョウ, imagine a new (ニュー) baby needing a diaper change: new -> ニュー, which sounds like ニョウ, and the diaper is full of urine.
urine
glycosuria; glucosuria; urine sugar
urethra
urination
urinary organs
diuresis
urination; micturition
urge to urinate
feces and urine; excreta; human waste
urea; carbamide
bloody urine; hematuria; haematuria
urine sampling; urine collection
urine bottle; (urinary) bedpan; chamber pot (esp. medical); urinal
excreta; raw sewage; human waste; night soil
urinalysis
type 1 diabetes; juvenile diabetes
type 2 diabetes; adult-onset diabetes
alkaptonuria; alcaptonuria
albuminuria
creatinurea; creatinuria