from The American Heritage® Dictionary of the English Language, 4th Edition
- transitive v. To oppose, deny, or take a pessimistic or negative view of: They will naysay any policy that raises taxes.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. Alternative spelling of nay-say. A refusal, denial, gainsay, disagreement or negation
- v. Alternative spelling of nay-say. say no to; deny, disagree, or oppose
From nay + say (Wiktionary)