no-no 
noun (plural no-nos) informal
A thing that is not possible or acceptable: perming highlighted hair used to be a definite no-no, but it’s now possible...
- So an office at that end of the building is a definite no-no as the droning hum could drive me mad.
- That sort of event was a definite no-no and he worked hard to prevent such things.
- Wiggling out was a definite no-no since he had already made sure that I had nowhere else to turn to.
Rhymes
- Monteverdian
- Monteverdi, Claudio
- Montevideo
- Montez, Lola
- Montezuma II
- Montezuma quail
- Montezuma's revenge
- Montfort, Simon de
- Montgolfier
- Montgomery
- Montgomery, Bernard Law
- Montgomery County
- Montgomery gland
- montgomeryite
- Montgomery, L. M.
- Montgomery's gland
- Montgomeryshire
- Montgomery's tubercle
- month
- month clock
- month-long
- monthly
- monthly meeting
- monthly nurse
- monthly rose