The word 'tampered' means to interfere with something in order to cause damage or change. There are many synonyms for the word 'most tampered,' which can describe a situation where something has been interfered with in an extreme way. Some common synonyms for 'most tampered' include: heavily manipulated, extensively altered, vastly modified, severely tampered with, significantly tampered, strongly edited, and hugely interfered. These synonyms can be used in various contexts, such as describing a document that has been changed beyond recognition, a photo that has been heavily edited, or a situation where evidence has been tampered with in a criminal investigation.