usage: the act of altering something secretly or improperly
Verb
1. tamper, fiddle, monkey, manipulate
usage: play around with or alter or falsify, usually secretively or dishonestly; "Someone tampered with the documents on my desk"; "The reporter fiddle with the facts"
2. meddle, tamper, intervene, step in, interfere, interpose
usage: intrude in other people's affairs or business; interfere unwantedly; "Don't meddle in my affairs!"