potlatch vs session

potlatch

verb
  • To carry out or take part in a potlatch ceremony. 

  • To give; especially, to give as a gift during a potlatch ceremony. 

noun
  • A communal meal to which guests bring dishes to share; a potluck. 

  • A ceremony amongst certain indigenous peoples of the Pacific Northwest in which gifts are bestowed upon guests and personal property is destroyed in a show of generosity and wealth. 

session

verb
  • To hold or participate in a jam session with other musicians. 

noun
  • Any of the three scheduled two hour playing sessions, from the start of play to lunch, from lunch to tea and from tea to the close of play. 

  • A period devoted to a particular activity, e.g. the annual or semiannual periods of a legislative body (that together comprise the legislative term) whose individual meetings are also called sessions. 

  • A meeting of a council, court, school, or legislative body to conduct its business. 

  • The sequence of interactions between client and server, or between user and system; the period during which a user is logged in or connected. 

  • An extended period of drinking, typically consuming beer with low alcohol content. 

  • An academic term 

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