hula hoop vs ringlet

hula hoop

noun
  • A toy in the form of a large hoop which is twirled around various parts of the body, especially the waist. 

verb
  • To use a hula hoop. 

ringlet

noun
  • A small ring. 

  • Any of various butterflies with small rings on the wings, in the tribe Satyrini of the family Nymphalidae, such as Aphantopus hyperantus. 

  • A lock, tress. 

verb
  • To surround or encircle like a ringlet. 

  • To form into ringlets. 

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