In elementary school, my third-grade teacher told me that the word gist (meaning “main idea”) stood for general idea statement. Until recently, I had accepted that as true without thinking about it. However, it’s pretty rare for acronym etymologies to be true, and this is no exception. The word originated as part of a legal term of art referring to “the real ground” of an action or indictment. That comes from the Anglo-Norman phrase cest action gist, or “this action lies”. The gist part of that is from the verb for “lie”, gesir, and gesir traces to Latin iacere, also “to lie”. Iacere (which is also the source of words like trajectory, jet, project, adjacent, and more) traces to the Proto-Italic reconstruction jakeo and ultimately Proto-Indo-European yeh, meaning “to throw”. According to Google Ngrams, gist has had a very inconsistent pattern of usage with peaks in several centuries and currently makes up 0.00011% of all English words.
