fir vs malus

fir

noun
  • Any pinaceous conifer of related genera, especially a Douglas fir (Pseudotsuga) or a Scots pine (Pinus sylvestris). 

  • A conifer of the genus Abies. 

  • Wood of such trees. 

malus

noun
  • A plant of the genus Malus (the apples). 

  • The loss or return of performance-related compensation originally paid by an employer to an employee as a result of the discovery of a defect in the performance. 

  • A penalty or negative thing. 

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