frequentative vs perennial

frequentative

adj
  • Serving to express repetition of an action. 

noun
  • Any of a subclass of imperfective verbs that denote a repeated action, no longer productive in English, but found in e.g. Finnish, Latin, Russian, and Turkish. 

perennial

adj
  • Appearing or recurring again and again; recurrent. 

  • Lasting or remaining active throughout the year, or all the time. 

  • Continuing without cessation or intermission for several years, or for an undetermined or infinite period; neverending or never failing; perpetual, unceasing. 

  • Of a plant: active throughout the year, or having a life cycle of more than two growing seasons. 

  • Appearing again each year; annual. 

noun
  • A plant that is active throughout the year, or has a life cycle of more than two growing seasons. 

  • A thing that lasts forever. 

  • A person or thing (such as a problem) that appears or returns regularly. 

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