the main or essential part of a matter: What was the gist of his speech?
2.
the ground of a legal action.
Origin: 1720–30; < Anglo-French (cest action) gist (this matter) lies, 3rd singular present indicative of Anglo-French, Old French gesir to lie ≪ Latin jacēre
the point or substance of an argument, speech, etc
2.
law the essential point of an action
[C18: from Anglo-French, as in cest action gist en this action consists in, literally: lies in, from Old French gésir to lie, from Latin jacēre, from jacere to throw]
1711, "the real point" (of a law case, etc.), from Anglo-Fr. legalese phrases, especially cest action gist "this action lies," meaning "this case is sustainable by law," from O.Fr. gist en "it consists in, it lies in" (third pers. sing. pres. indicative of gésir "to lie"), from L. jacet "it lies."