The Collaborative International Dictionary of English v.0.48:

Negative \Neg"a*tive\ (n[e^]g"[.a]*t[i^]v), v. t. [imp. & p. p.
   Negatived (n[e^]g"[.a]*t[i^]vd); p. pr. & vb. n.
   Negativing.]
   1. To prove unreal or untrue; to disprove.
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            The omission or infrequency of such recitals does
            not negative the existence of miracles. --Paley.
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   2. To reject by vote; to refuse to enact or sanction; as, the
      Senate negatived the bill.
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   3. To neutralize the force of; to counteract.
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