1. Morally binding or necessary
   "it is incumbent on me to attend"

See also: irremissible, obligatory

• no-good
• no-hit
• no-hit game
• no-hitter
• no-hoper
• no-no
• no-nonsense
• no-par stock
• no-par-value stock
• no-parking zone
• no-see-um
• no-show
• no-side
• no-trump
• no-win
• no-win situation
• NOAA
• Noachian
• Noachian deluge
• Noah
• Noah and the Flood
• Noah Webster
• Noah's flood
• Noam Chomsky
• nob