Tamper means to touch or change something without permission or without enough knowledge of how it works. It can also mean to interfere with or meddle with something, especially to damage or corrupt it. A tamper is also a tool with a long handle and a heavy, square base used for leveling and firmly packing materials such as dirt, clay, sand, and gravel. It is used for packing and leveling dirt, sand, and rock, as well as many other materials.