Correct

骨子里

/ gǔzilǐ /
Strokes

Definition

beneath the surface/fundamentally/at the deepest level

Example

As a Noun

in one's heart of hearts; at heart

1
zi
骨子里
háishi
还是
wèi
ài
可爱
de
nóngmín
农民
  

He is still a lovely farmer at heart.

2
Cóng
zi
骨子里
qiáo
瞧不起

look down upon sb in one's heart of hearts

As a Noun

personal; private

3
Zhè
shì
men
他们
zi
骨子里
de
shì
  

It's their private affair.