Related Clues:

• Sister's outfit
• Something prohibited
• Taboo practice
• It's inadvisable
• Improper act
• Sticking a fork in the toaster, e.g.
• Toddler's taboo
• Monk's robe
• Something taboo
• Moral philosophy topic
• Kid's taboo
• Thing to shun
• Established practice
• ''___ Nanette''
• It's tough to break one