From Longman Dictionary of Contemporary Englishtampertam‧per /ˈtæmpə $ -ər/ verb → tamper with something→ See Verb table
Examples from the Corpus
tamper• History is littered with examples of people tinkering, tampering and then tumbling.• They're investigating allegations of interference with witnesses and tampering with evidence in a forthcoming trial.• The Budget Resolution contained no tax increase and no tampering with Social Security.• Dougal almost felt he was tampering with something he could neither understand nor control.• Both have vigorously denied tampering with the ball.• Orthodoxy, by its very nature, disapproves of tampering with tradition.From Longman Business Dictionarytampertam‧per /ˈtæmpə-ər/ verb → tamper with something→ See Verb tableOrigin tamper (1500-1600) Probably from temper 