Related Clues:

• It's not allowed
• Improper act
• Sticking a fork in the toaster, e.g.
• Toddler's taboo
• Something taboo
• Moral philosophy topic
• Proscribed by society as improper
• Kid's taboo
• Thing to shun
• Ghoulish no no
• Anathema
• ''___ Nanette''
• Verboten (Var.)
• Unacceptable
• Impermissible