gingernut vs umber

gingernut

noun
  • A redhead; a ginger-haired person. 

  • A hard biscuit, flavoured with powdered ginger, often dunked in tea. 

umber

noun
  • A grayling. 

  • A dusky brown African wading bird (Scopus umbretta) allied to the shoebill and herons; a hamerkop. 

  • A brown clay, somewhat darker than ochre, which contains iron and manganese oxides. 

adj
  • Of a reddish brown colour, like that of the pigment. 

verb
  • To give a reddish-brown colour to. 

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