mega vs perfective

mega

adj

  • Great; excellent. 

  • Very large. 

noun

  • The Steinhaus-Moser number ② 

adv

  • extremely 

perfective

adj

  • Of, or relative to, the perfect tense or perfective aspect. 

noun

  • a perfective verb form 

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