Final answer:
The combining form lith/o means 'stone, calculus', which is related to medical conditions like renal calculi, or kidney stones.
Step-by-step explanation:
The CF (combining form) lith/o means stone, calculus. This term is commonly used in medical terminology relating to the kidneys and urinary system. For example, renal calculi (also known as kidney stones) are solid concretions of dissolved minerals in urine. Nephrolithiasis is when these stones are formed inside the kidneys, while urolithiasis refers to stones present in the bladder. A large kidney stone may block the ureter, which can result in decreased kidney function and damage to the kidney.