On non contrast ct scan it says ill defined hypodense area on hepatic lobe. does ill defined mean not clear margins?

Yes: Without iv contrast, the CT scan is only good for identifying if there is a lesion but cannot characterize what it looks like, what type of blood supply or other markers that help to identify what it might be. The only lesion that a non-contrast CT of the liver can clearly see is a liver cyst(s), which do not need contrast, since the liver is different than the fluid in the cyst.