I have a large, hard lump felt under the skin of ,my right temple. noticed it 5/6 years ago. the skin moves freely around it, could is be cancer?

Hard lump: It is definitely not cancer! It may represent a lipoma (fatty growth)

Unlikely: These are usually calcium deposits that arise after some form of trauma at that site that triggers a bone healing reaction. Some can become quite prominent. Your doc could confirm or exclude the possibility. I wouldn't lose sleep over it or go in just for this. Just ask during another encounter.