by proxy vs secondhand

by proxy

secondhand

noun
  • Secondhand goods (especially clothes) collectively. 

adv
  • In a used or previously-owned condition. 

  • indirectly 

adj
  • inhaled from the air near someone else smoking. 

  • Not new; previously owned and used by another. 

  • Indirect; from a secondary source; not firsthand. 

  • Dealing in such merchandise. 

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