pith

[1]	core , heart , kernel , nucleus , crux , gist , focus , focal point , essence , meat , marrow , nub , point , spirit , substance , quintessence
[2]	weight , kernel , substance , burden , gravamen , core , center , gravity , force , centre , essence , moment , import , gist , heart , importance , significance , heart and soul , inwardness , substance , depth , marrow , meat , matter , nub , sum , nitty-gritty