Related Clues:
- "Negatory!"
- ... by Italian one either way in London, on order
- Numbers of a nonstarter
- Prohibited practice
- Modern composer's rules of grammar: double negatives are a ___ ?
- Impossibility
- Something totally unacceptable (informal)
- Wrong numbers
- Possibility that's not an option
- Something that must not be done
- Second helping, to a dieter
- 'What were you thinking?!'
- Taboo, to a child
- Social impropriety
- Something you might get your hand slapped for doing