The verb 'tamper' emerged in the mid-16th century, originally meaning 'to busy oneself with, to work in a tentative manner'. It is believed to be an alteration of the Middle English word 'temper', which meant 'to bring something to a proper state, to mix or modify'. This connection is logical, as 'tempering' metal involves carefully modifying its properties. Over time, the sense of 'tamper' shifted from tentative work to improper or harmful interference, likely influenced by the idea of meddling with something to alter its intended state. The modern meaning of interfering with something, especially with malicious or unauthorized intent, became firmly established by the 19th century.

The word 'tamper' is a simplex verb of uncertain origin, likely a dialectal variant of the verb 'temper'. Its functional role is as a lexical verb.