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n. pl. no-noes Informal
1. Something unacceptable or impermissible: "Even though his company wasn't the one involved in the case, what he did is considered a definite no-no" (Mike Royko).
2. A social blunder; a faux pas.
3. Baseball A game in which a pitcher allows no hits and no runs.
American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
n., pl. -nos, -no's.
Informal. anything that is forbidden or not advisable, as because of being improper or unsafe.
Random House Kernerman Webster's College Dictionary, © 2010 K Dictionaries Ltd. Copyright 2005, 1997, 1991 by Random House, Inc. All rights reserved.
no-no[ˈnəʊnəʊ] N that's a no-no (= undesirable) → eso no se hace; (= not an option) → no existe tal posibilidad
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