nub

nub - English Dictionary

[ noun ]
■ the choicest or most essential or most vital part of some idea or experience
e.g.)
・the nub of the story
→ center , centre , core , essence , gist , heart , heart and soul , inwardness , kernel , marrow , meat , nitty-gritty , pith , substance , sum

[ noun ]
■ a small piece
e.g.)
・a nub of coal
→ stub

[ noun ]
■ a small lump or protuberance
→ nubble