efficient vs working

efficient

adj
  • effective, efficacious 

  • expressing the proportion of consumed energy that was successfully used in a process; the ratio of useful output to total input 

  • causing effects, producing results; bringing into being; initiating change (rare except in philosophical and legal expression efficient cause = causative factor or agent) 

  • making good, thorough, or careful use of resources; not consuming extra. Especially, making good use of time or energy 

working

adj
  • Used in real life; practical. 

  • In paid employment. 

  • Enough to allow one to use something. 

  • Of or relating to employment. 

  • That suffices but requires additional work. 

  • That is or are functioning. 

noun
  • Method of operation. 

  • Becoming full of a vegetable substance. 

  • Operation; action. 

  • The incidental or subsidiary calculations performed in solving an overall problem. 

  • A train movement. 

  • Fermentation. 

  • A place where work is carried on. 

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