egret vs whitecap

egret

noun
  • Any of various wading birds of the genera Egretta or Ardea that includes herons, many of which are white or buff, and several of which develop fine plumes during the breeding season. 

  • A plume or tuft of feathers worn as a part of a headdress, or anything imitating such an ornament. 

  • The flying feathery or hairy crown of seeds or achenes, such as the down of the thistle. 

whitecap

noun
  • Any of several birds having a white patch on the head 

  • A wave having a white crest; a breaker 

  • A member of a self-appointed vigilante committee that carried out lynchings. Some early ones wore white hoods or masks. 

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