erstwhile vs old

erstwhile

adj
  • Former, previous. 

  • Respected, honourable. 

old

adj
  • Former, previous. 

  • A grammatical intensifier, often used in describing something positive, and combined with another adjective. 

  • Having been used and thus no longer new or unused. 

  • Of a living being, having lived for most of the expected years. 

  • Of an object, concept, relationship, etc., having existed for a relatively long period of time. 

  • That is no longer in existence. 

  • Having existed or lived for the specified time. 

  • Tiresome after prolonged repetition. 

  • Of a species or language, belonging to a lineage that is distantly related others 

  • Obsolete; out-of-date. 

  • Said of subdued colors, particularly reds, pinks and oranges, as if they had faded over time. 

  • Being a graduate or alumnus of a school, especially a public school. 

  • Indicating affection. 

  • Of a perishable item, having existed for most of, or more than, its shelf life. 

  • Familiar. 

noun
  • One's parents. 

  • People who are old; old beings; the older generation, taken as a group. 

  • A person older than oneself, especially an adult in relation to a teenager. 

  • A typically dark-coloured lager brewed by the traditional top-fermentation method. 

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