lə̇ˈthīəsə̇s noun
( plural lithia·ses -ˌsēz)
Etymology: New Latin, from Greek, from lith- + -iasis
1. : the formation or presence of stony concretions in the body (as in the urinary tract and gall bladder) — usually used in combination
chole lithiasis
nephro lithiasis
2. : an abnormal development of sclerotic or grit cells in a plant (as the pear)