1. To meddle; to be busy; to try little experiments; as, to tamper with a disease. 'T is dangerous tampering with a muse. (Roscommon)
2. To meddle so as to alter, injure, or vitiate a thing.
3. To deal unfairly; to practice secretly; to use bribery. Others tampered For Fleetwood, Desborough, and lambert. (Hudibras)
Origin: A corruption of temper.