Related Clues:
- Scrubbed, as a NASA mission
- 'Ain't happenin''
- Something frowned upon
- Canceled at 6-Down
- An unacceptable thing
- Double negative
- Double-negative taboo
- 'Don't touch that, honey!'
- Scrapped mission
- Rocket launch cancellation
- Nonstarter
- Tyke's taboo
- Aborted operation
- Like a scratched space shot
- Taboo to a toddler