An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

1) To deny the existence or truth of.
2) To cause to be ineffective or invalid.

From L. negatus p.p. of negare "to say 'no', deny," from Old L. nec "not," from PIE base *ne- "no, not."

Nâyidan infinitive from nâ "no, not," variants na, ni, ma- (prohitive); from Mid.Pers. nê, ma "no, not;" O.Pers. naiy, nai "not;" Av. nôit, naē "not;" cf. Skt. ná "not;" cf. L. ne-, in-, un-; Gk. ni; Lith. nè; O.C.S. ne "not;" PIE *ne-, as above.