custom vs usage

custom

noun
  • Traditional beliefs or rituals. 

  • Frequent repetition of the same behavior; way of behavior common to many; ordinary manner; habitual practice; method of doing, living or behaving. 

  • Habitual buying of goods; practice of frequenting, as a shop, factory, etc., for making purchases or giving orders; business support. 

  • Long-established practice, considered as unwritten law, and resting for authority on long consent. Compare prescription. 

  • A custom (made-to-order) piece of art, pornography, etc. 

adj
  • Created under particular specifications, specially to fit one's needs: specialized, unique, custom-made. 

  • Own, personal, not standard or premade. 

usage

noun
  • Custom, tradition. 

  • The established custom of using language; the ways and contexts in which spoken and written words are used, especially by a certain group of people or in a certain region. 

  • A custom or established practice. 

  • The act of using something; use, employment. 

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