tamperyoudaoicibaDictYouDict
tamper: [16] Tamper began life as a variant of temper. It originally meant ‘mix clay together with water to make it suitable for use’. However, the notion of ‘mixing’ seems to lead on naturally to ‘interference’ (meddle originally meant ‘mix’), and by the end of the 16th century we find that ‘tampering with clay’ had moved on to ‘tampering with anything’ – ‘interfering’ with it.
=> temper
tamper (v.)youdaoicibaDictYouDict
"meddle, interfere," 1560s, figurative use of tamper "to work in clay, etc., so as to mix it thoroughly," probably originally a variant of temper (v.), which is how it often was spelled at first. Perhaps it is a dialectal workmen's pronunciation. Related: Tampered; tampering.
tamper (n.)youdaoicibaDictYouDict
"one who or that which tamps," 1864, agent noun from tamp (v.).