the main or essential part of a matter

What was the gist of his speech?

the ground of a legal action.

noun

basis , bearing , bottom line * , burden , core , drift , force , heart , idea , import , kernel * , keynote , marrow , matter , meat * , name of the game * , nature of the beast , nitty gritty , nuts and bolts * , pith * , point , punch line , quintessence , score , sense , short , significance , soul , spirit , stuff * , subject , substance , summary , tenor , theme , thrust , topic , upshot * , essence , kernel , meat , nub , pith , root , stuff , bottom line , meaning , sum and substance , upshot