adequate vs second string

adequate

det
  • A sufficient amount of; enough. 

adj
  • Equal to or fulfilling some requirement. 

second string

adj
  • Not as good; of a lower quality or condition. 

noun
  • A unit of players which is considered to have a secondary level of talent and which usually plays after the first string. 

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