Related Clues:
- Large lunch sandwich, for short
- Undersea craft (Abbr.)
- Undersea vessel
- Voyager to the bottom of the sea
- Banned thing
- ... 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
- Long deli sandwich