gist /dʒɪst/ BrE AmE noun
[ Date: 1700-1800 ; Language: Anglo-French ; Origin: 'it lies, it can be presented in a court of law' , from Old French gesir 'to lie' ]
the gist the main idea and meaning of what someone has said or written
the gist of
The gist of his argument is that full employment is impossible.
Don’t worry about all the details as long as you get the gist (=understand the main meaning) of it.