Related Clues:

• Deadly or mortal thing
• Prohibited activity
• Commandment taboo
• It's not a good thing
• Seminary subject
• Church no-no
• Society no-no
• Social no-no
• One of the seven deadlies
• Priest's concern
• Pride, e.g.
• Church topic
• Like forbidden fruit
• Out of bounds
• See 38-Down