1. main rotor rotor consisting of large rotating airfoils on a single-rotor helicopter that produce the lift to support the helicopter in the air
  2. mandatory required by rule
  3. mentor a wise and trusted guide and advisor
  4. maniraptor advanced carnivorous theropod
  5. monitor someone who observes to ensure fairness or prevent mistakes
  6. main road a major road for any form of motor transport
  7. mandator an authority who issues a mandate
  8. migrator traveler who moves from one region or country to another
  9. narrator someone who tells a story
  10. minority being or relating to the smaller in number of two parts
  11. manroot tropical American prostrate or climbing herbaceous perennial having an enormous starchy root; sometimes held to be source of the sweet potato
  12. money order a written order for the payment of a sum to a named individual; obtainable and payable at a post office
  13. generator someone who originates, causes, or initiates something
  14. minor term the term in a syllogism that is the subject of the conclusion
  15. moderator someone who presides over a debate or meeting
  16. migratory (of animals) moving seasonally
  17. minatory threatening or foreshadowing evil or tragic developments
  18. minaret a slender tower with balconies, especially on a mosque
  19. inheritor a person who is entitled by law or by the terms of a will to inherit the estate of another
  20. mail order a purchase negotiated by mail