Informal An unsupported statement or assurance.(noun)
Informal An authoritative expression of permission or approval.(noun)
Informal The right or authority to decide.(noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
Use "say-so" in a sentence
"What did surprise me was the number of letters from readers who were put off by my willingness to give my husband broad say-so in terms of my discretionary spending."
"We don't have the final say-so – therefore we do not judge."
"They have the authority (and the numbers) to bring the issue to the floor without Quinn's say-so."