Main Entry: tam·per

Pronunciation: \ˈtam-pər\

Function: intransitive verb

Inflected Form(s): tam·pered; tam·per·ing \-p(ə-)riŋ\

Etymology: probably from Middle French temprer to temper, mix, meddle — more at temper

Date: 1567

1 : to carry on underhand or improper negotiations (as by bribery)
2 a : to interfere so as to weaken or change for the worse —used with with <did not want to tamper with tradition> b : to try foolish or dangerous experiments —used with with c : to render something harmful or dangerous by altering its structure or composition <was charged with tampering with consumer products>

— tam·per·er \-pər-ər\ noun

— tam·per·proof \ˈtam-pər-ˌprüf\ adjective