no-no

[ noh-noh ]
/ ˈnoʊˌnoʊ /

noun, plural no-nos, no-no's. Informal.

anything that is forbidden or not advisable, as because of being improper or unsafe: If you want to lose weight, rich desserts are a no-no.

Origin of no-no

1940–45, Americanism; reduplication of no1
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for nono

British Dictionary definitions for nono

Nono
/ (Italian ˈnɔːno) /

noun

Luigi (luˈiːdʒi). 1924–90, Italian composer of 12-tone music
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012