pyramidal vs pyramidic

pyramidal

adj

  • Pyramid-shaped. 

  • Tetragonal. 

noun

  • One of the carpal bones. 

pyramidic

adj

  • Of or pertaining to a pyramid; having the form or imposing presence of a pyramid; pyramidal. 

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