tamper

1. (intransitive) To make unauthorized or improper alterations, sometimes causing deliberate damage; to meddle (with something).Examples: "tamper detection"; "The alarm had been tampered with and didn’t go off when it should have."; "The election monitors found that a large number of ballots had been tampered with."Synonyms: interfereintransitive

2. (intransitive) To try to influence someone, usually in an illegal or devious way; to try to deal (with someone).Examples: "Prosecutors argued that he would tamper with witnesses if bail was granted."; "[…] no man knowes whether a Wife and a Mother, which had such a latitude of power over the Father and the Sonne, would not be tampering with a Prince (even in the point of Religion) of so tender years as rendred him fit for any impression, and to be indoctrinated with such principles as well concerning Religion, as others best suitable to her own designes."; "[…] as these passions and principles are inalterable, it may be thought, that our conduct, which depends on them, must be so too, and that ’twou’d be in vain, either for moralists or politicians, to tamper with us, or attempt to change the usual course of our actions, with a view to public interest."intransitive

3. (dated) To meddle (with something) in order to corrupt or pervert it.Examples: "[…] No Art used to inflame him, no Coquetry practised to tempt or intice him, and no Prudery or Affectation to tamper with his Passions; but, on the contrary, artless and unpractised in the Wiles of the World, all her Endeavours, and even all her Wishes, tended only to render herself as un-amiable as she could in his Eyes:"; "She therefore dissuaded Julia from attempting to tamper with the honesty of a servant who had the keys of the vaults […]"; "Is it not the tendency, born of Reconstruction and Reaction, to found a society on lawlessness and deception, to tamper with the moral fibre of a naturally honest and straightforward people until the whites threaten to become ungovernable tyrants and the blacks criminals and hypocrites?"dated

4. (obsolete) To involve oneself (in a plot, scheme, etc.).Examples: "1716, Joseph Addison, The Free-holder, No. 31, 6 April, 1716, London: D. Midwinter and J. Tonson, p. 180, […] he was beheaded upon the Defeat of the Conspiracy for having but thus far tampered in it."obsolete

5. (obsolete) To attempt to practise or administer something (especially medicine) without sufficient knowledge or qualifications.Examples: "Certainly it is a scurvy strong troublesom purge, therefore ill to be tamperd with by the unskilful […]"; "[…] Corners of Streets were plaster’d over with Doctors Bills, and Papers of ignorant Fellows; quacking and tampering in Physick, and inviting People to come to them for Remedies;"; "[…] by reason of his continual studies, and the head-ach, to which he was subject from his youth, and his perpetual tampering with physic, his eyes had been decaying for twelve years before."obsolete

6. (US, Canada, in professional sports) To discuss future contracts with a player, against league rules.Synonyms: tap upCanadaUS