falsify

(verb) make false by mutilation or addition; as of a message or story. Synonyms: distort, garble, warp.

(verb) tamper, with the purpose of deception. Synonyms: fudge, manipulate, fake, cook, wangle, misrepresent. Examples: "Fudge the figures." "Cook the books." "Falsify the data."

(verb) prove false. Examples: "Falsify a claim."

(verb) falsify knowingly. Examples: "She falsified the records."

(verb) insert words into texts, often falsifying it thereby. Synonyms: interpolate, alter.