incessive vs perpetual

incessive

adj
  • Continual or successive; unceasing. 

  • Insightful; deep and succinct; incisive. 

  • Intruding inward. 

  • Tending to incite or inflame; incensive. 

  • Intense and active. 

  • Synonym of inessive 

  • Fierce; cruel and aggressive. 

  • Critical and accurate; incisive. 

  • Included. 

  • Durative. 

perpetual

adj
  • Continuing; uninterrupted. 

  • Set up to be in effect or have tenure for an unlimited duration. 

  • Lasting forever, or for an indefinitely long time. 

  • Flowering throughout the growing season. 

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