cilium vs feeler

cilium

noun
  • One of the fine hairs along an insect's wing. 

  • An eyelash. 

  • A short microscopic hairlike organelle projecting from a eukaryotic cell (such as a unicellular organism or one cell of a multicelled organism) which serve either for propulsion by causing currents in the surrounding fluid or as sensors. 

  • Hairs or similar protrusions along the margin of an organ. 

feeler

noun
  • An antenna or appendage used for feeling, especially on an insect. 

  • Someone or something that feels. 

  • Someone that assumes or imagines that one's affection is reciprocated; Someone that indulges in one's own wishful thinking; One who flatters oneself 

  • Something ventured to test another's feelings, opinion, or position. 

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