axipetal vs centripetal

axipetal

adj
  • Tending toward the center or axis 

centripetal

adj
  • Directed or moving towards a centre. 

  • Directed towards the central nervous system; afferent. 

  • Of, relating to, or operated by centripetal force. 

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