What is varicocele urolithiasis?

No such thing: Urolithiasis means presence of stones in the urinary tract, i.e. In the kidney, ureter or bladder. More rarely in the urethra. A varicocele is an abnormality of the spermatic vein or veins and is not connected or part of the urinary tract.

Here is...: I assumed you probably meant varicocele phlebolith, not urolithiasis. Urolithiasis denotes stones forming inside urinary tract - kidneys, ureters, ; bladder. Phlebolith indicates stone formed inside vein, usually at its valves as the phlebolith commonly seen in pelvic veins in imaging study, which carries no practical weight in clinical care. So, i assumed stones similarly forms inside varicocele.