-n't shortened (enclitic) form of not¹

NT

1. National Theatre (now known as RNT)
2. National Trust
3. New Testament
4. Northern Territory (Aust)
5. Northwest Territories (of Canada)
6. No trumps (cards)

• sinfulness
• sinfulnesses
• sing
• sing.
• singable
• singableness
• singablenesses
• sing along
• singalong
• sing another song
• sing another tune
• Singaporean
• Singapore Sling
• singe
• singed
• singed cat
• singed cats
• singeing
• singer
• singers
• singer-songwriter
• singer-songwriters
• singes
• Singhalese
• singing