fluctuation vs vibration

fluctuation

noun
  • A wavering; unsteadiness. 

  • In medicine, a wave-like motion or undulation of a fluid in a natural or abnormal cavity (e.g. pus in an abscess), which is felt during palpation or percussion. 

  • A motion like that of waves; a moving in this and that direction. 

vibration

noun
  • The act of vibrating or the condition of being vibrated. 

  • A single complete vibrating motion. 

  • An instinctively sensed emotional aura or atmosphere. 

  • A vibrational energy of spiritual nature through which mediumistic and other paranormal phenomena are conveyed or affected. 

  • Any periodic process, especially a rapid linear motion of a body about an equilibrium position. 

How often have the words fluctuation and vibration occurred in a corpus of books? (source: Google Ngram Viewer )