persistent vs spasmodic

persistent

adj
  • Insistently repetitive. 

  • Of data or a data structure: not transient or temporary, but remaining in existence after the termination of the program that creates it. 

  • Describing a fractal process that has a positive Brown function 

  • Lasting past maturity without falling off. 

  • non-transient. 

  • Obstinately refusing to give up or let go. 

  • Indefinitely continuous. 

spasmodic

adj
  • Intermittent or fitful; occurring in abrupt bursts. 

  • Convulsive; consisting of spasms. 

  • Of or relating to a spasm; resembling a sudden contraction of the muscles. 

  • Erratic or unsustained. 

  • Of or relating to the spasmodic poets, a group of British Victorian poets who wrote introspective drama in verse. 

noun
  • A medicine for suppressing spasms. 

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