1. absolute frequency the number of observations in a given statistical category
  2. Nyquist frequency (telecommunication) twice the maximum frequency occurring in the transmitted signal
  3. audio frequency an audible acoustic wave frequency
  4. absolute viscosity a measure of the resistance to flow of a fluid under an applied force
  5. absoluteness the quality of being absolute
  6. obsolete no longer in use
  7. absolute value a real number regardless of its sign
  8. relative frequency the ratio of the number of observations in a statistical category to the total number of observations
  9. infrared frequency the infrared region of the electromagnetic spectrum
  10. radio frequency an electromagnetic wave frequency between audio and infrared
  11. absolute ceiling the maximum altitude at which an airplane can maintain horizontal flight
  12. subsequent following in time or order
  13. absolute threshold the lowest level of stimulation that a person can detect
  14. low frequency 30 to 300 kilohertz
  15. absolutely totally and definitely; without question
  16. absolute zero the lowest temperature theoretically attainable
  17. very low frequency 3 to 30 kilohertz
  18. obsolescence falling into disuse or becoming out of date
  19. abstinence the trait of refraining from something, especially alcohol
  20. obsoleteness the property of being out of date and not current