colloquial vs informal

colloquial

adj
  • Characteristic of familiar conversation, of common parlance; informal. 

  • Of or pertaining to a conversation; conversational or chatty. 

noun
  • A colloquial word or phrase, colloquialism 

informal

adj
  • Reflecting everyday, non-ceremonious usage. 

  • Suited for everyday use. 

  • Not in accord with the usual regulations. 

  • Not formal or ceremonious. 

  • Not organized; not structured or planned. 

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