xīn​xīn​kǔ​kǔ

painstakingly

辛辛苦苦 xīn​xīn​kǔ​kǔ
painstakingly descriptive
with great effort, toil, or hardship

He worked hard all his life and finally supported his children through college.

Frequency

Movie subtitles
1.40 per million appears in 1% of films
Written text
3.09 per million

Sources

Definitions
CC-CEDICT