1. cantus firmus a melody used as the basis for a polyphonic composition
  2. manual of arms (military) a prescribed drill in handling a rifle
  3. dental floss a soft thread for cleaning the spaces between the teeth
  4. removal firm a company that moves the possessions of a family or business from one site to another
  5. dental caries soft decayed area in a tooth
  6. rental income income received from rental properties
  7. frontal gyrus any of the convolutions of the outer surface of the frontal lobe of the cerebrum
  8. vital force (biology) a hypothetical force (not physical or chemical) once thought by Henri Bergson to cause the evolution and development of organisms
  9. Anguilliformes elongate fishes with pelvic fins and girdle absent or reduced
  10. mental process the performance of some composite cognitive activity
  11. needle furze prickly yellow-flowered shrub of the moors of New England and Europe
  12. friendly fire fire that injures or kills an ally
  13. frontal cortex that part of the cerebral cortex in either hemisphere of the brain lying directly behind the forehead
  14. terra firma the solid part of the earth's surface
  15. coat of arms the official symbols of a family, state, etc.
  16. frontal sinus one of a pair of cavities in the frontal bone
  17. can of worms a source of unpredictable trouble and complexity
  18. Anatole France French writer of sophisticated novels and short stories
  19. mendelevium a radioactive transuranic element synthesized by bombarding einsteinium with alpha particles (Md is the current symbol for mendelevium but Mv was formerly the symbol)
  20. oriental person a member of an Oriental race