marrow; pith; quintessence; essence

jīng suǐ

j+īng·1st tones+uǐ·3rd tone

Examples2 available

Individual freedom is the soul of democracy.

个人自由是民主的精髓。

It's really unfortunate. You don't understand at all its essence.

太可惜了，你一点也不懂它的精髓。